Relevant bibliographies by topics / Charge transfer insulator

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Charge transfer insulator'

Author: Grafiati
Published: 4 June 2021
Last updated: 15 February 2022

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Journal articles on the topic "Charge transfer insulator"

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Ōno, Yoshiaki, Tamifusa Matsuura, and Yoshihiro Kuroda. "Kondo Insulator and Charge Transfer Insulator in Lattice Anderson Model." Journal of the Physical Society of Japan 63, no. 4 (April 15, 1994): 1406–21. http://dx.doi.org/10.1143/jpsj.63.1406.

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Guo, Wei, and Rushan Han. "From Charge Transfer Type Insulator to Superconductor." International Journal of Modern Physics B 17, no. 18n20 (August 10, 2003): 3347–53. http://dx.doi.org/10.1142/s021797920302096x.

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We propose a microscopic model Hamiltonian to account for impurity doping induced insulator-superconductor transition and the coexistence of antiferromagnetism and superconductivity in the high-Tc cuprates. The crossover from non Fermi liquid to Fermi liquid regime characterized by delocalization of d electrons on Cu sites is discussed.
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Nagae, Moichiro. "Charge transfer and coherent charge propagation in metal-insulator junctions." Physical Review B 36, no. 17 (December 15, 1987): 9025–44. http://dx.doi.org/10.1103/physrevb.36.9025.

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Saito, Gunzi, and Tsuyoshi Murata. "Mixed valency in organic charge transfer complexes." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 366, no. 1862 (September 10, 2007): 139–50. http://dx.doi.org/10.1098/rsta.2007.2146.

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Mixed-valence (partial charge transfer state) and segregated stacking are the key factors for constructing organic metals. Here, we discuss the ionicity phase diagrams for a variety of charge transfer systems to provide a strategy for the development of functional organic materials (Mott insulator, semiconductor, superconductor, metal, complex isomer, neutral–ionic system, etc.).
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Kwon, Choi, Bae, and Park. "Hysteresis Reduction for Organic Thin Film Transistors with Multiple Stacked Functional Zirconia Polymeric Films." Crystals 9, no. 12 (November 28, 2019): 634. http://dx.doi.org/10.3390/cryst9120634.

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We show that transfer hysteresis for a pentacene thin film transistor (TFT) with a low-temperature solution-processed zirconia (ZrOx) gate insulator can be remarkably reduced by modifying the ZrOx surface with a thin layer of crosslinked poly(4-vinylphenol) (c-PVP). Pentacene TFTs with bare ZrOx and c-PVP stacked ZrOx gate insulators were fabricated, and their hysteresis behaviors compared. The different gate insulators exhibited no significant surface morphology or capacitance differences. The threshold voltage shift magnitude decreased by approximately 71% for the TFT with the c-PVP stacked ZrOx gate insulator compared with the bare ZrOx gate insulator, with 0.75 ± 0.05 and 0.22 ± 0.03 V threshold voltage shifts for the bare ZrOx and c-PVP stacked ZrOx gate insulators, respectively. The hysteresis reduction was attributed to effectively covering hysteresis-inducing charge trapping sites on ZrOx surfaces.
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Oleś, Andrzej M., and Marek Kamiński. "Metal–antiferromagnetic insulator transition in the charge-transfer model." Physical Review B 52, no. 21 (December 1, 1995): 15111–14. http://dx.doi.org/10.1103/physrevb.52.15111.

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Bang, Y., C. Castellani, M. Grilli, G. Kotliar, R. Raimondi, and Z. Wang. "SINGLE PARTICLE AND OPTICAL GAPS IN CHARGE-TRANSFER INSULATORS." International Journal of Modern Physics B 06, no. 05n06 (March 1992): 531–45. http://dx.doi.org/10.1142/s0217979292000311.

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We analyze the collective excitations near a Mott-Hubbard and a metal charge transfer insulator transition, using the slave boson technique. We show that the Mott transition can be viewed as an excitonic softening, which takes place when the bound state between the lower and upper Hubbard bands reaches zero energy. The exciton energy is related to the jump of the chemical potential at zero doping. In a charge transfer insulator this mode describes a p-d charge fluctuation, i.e. it is a charge transfer exciton. In the single band Hubbard model the excitonic resonance describes virtual transitions between the lower and the upper Hubbard band. Finally we contrast the behaviour of the collective modes near the Mott transition with and near the Charge Transfer Instability. In the former the exciton energy and the charge compressibility go to zero. In the latter the exciton energy remains finite and the charge susceptibility diverges, causing phase separation.
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Fischer, Mark H., Si Wu, Michael Lawler, Arun Paramekanti, and Eun-Ah Kim. "Nematic and spin-charge orders driven by hole-doping a charge-transfer insulator." New Journal of Physics 16, no. 9 (September 30, 2014): 093057. http://dx.doi.org/10.1088/1367-2630/16/9/093057.

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Zhao, Jianjun, Matthias Wasem, Christopher R. Bradbury, and David J. Fermín. "Charge Transfer across Self-Assembled Nanoscale Metal−Insulator−Metal Heterostructures." Journal of Physical Chemistry C 112, no. 18 (April 15, 2008): 7284–89. http://dx.doi.org/10.1021/jp7101644.

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Phillips, J. C. "Charge transfer and superconductor-metal-insulator transitions in high-Tcsuperconductors." Physical Review B 51, no. 21 (June 1, 1995): 15402–6. http://dx.doi.org/10.1103/physrevb.51.15402.

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Dissertations / Theses on the topic "Charge transfer insulator"

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Grisolia, Mathieu. "Nouveaux états électroniques d'interface à partir d’isolants corrélés." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS239/document.

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Les oxydes de métaux de transition (Ti, Fe, Mn, Cu, etc) présentent une multitude de fonctionnalités tout en cristallisant dans un nombre réduit de structures. C’est le cas par exemple dans la famille des pérovskites qui arborent de nombreux ordres électroniques (isolants, métaux, supraconducteurs) et magnétiques (ferro- et antiferromagnétiques). La compatibilité structurale de ces différents composés permet de les combiner au sein d'hétérostructures multifonctionnelles mais aussi, dans certains cas, de faire émerger de nouvelles propriétés aux interfaces. Un exemple typique découvert en 2004 est celui du gaz électronique bidimensionnel se formant à l'interface entre deux isolants de bande, LaAlO₃ et SrTiO₃ .S’inspirant de ce résultat majeur, ce travail de thèse a pour but de générer de nouvelles phases électroniques et magnétiques aux interfaces, non à partir d'isolants de bande mais d'isolants de Mott et d'isolants à transfert de charge. A l'interface entre ces deux types de composés, l’alignement de bande est rendu plus complexe par la présence de fortes corrélations électroniques.Ainsi, les reconstructions d’interface peuvent donner lieu à une déstabilisation de l'état fondamental, et à la génération de nouvelles phases magnétiques, conductrices ou supraconductrices absentes du diagramme de phase du matériau massif.Dans un premier temps, lors de ce travail nous avons synthétisé, par ablation laser pulsé des couches minces d'isolants de Mott, les titanates de terre-rare (RTiO₃ ). Nous avons caractérisé leurs propriétés magnétiques, optiques et électroniques.Dans un second temps, nous avons également optimisé des couches minces d’isolants à transfert de charge, les nickelates de terre-rare (RNiO₃ ). Nous avons étudié en détail l’effet du rayon ionique de la terre-rare sur la structure électronique à basse température de ces composés.Le cœur de ce travail de thèse a été l'étude des propriétés de l’interface formée par ces deux constituants via une combinaison de plusieurs techniques de spectroscopie (absorption de rayonnement synchrotron, XAS, dichroïsme linéaire et circulaire, XMCD, et spectroscopie de perte d’énergie, STEM-EELS) en lien avec des calculs ab-initio.Après avoir démontré l’apparition d’une nouvelle phase ferromagnétique dans les nickelates, nous discutons du rôle des corrélations dans les nickelates sur le transfert de charge et sur la reconstruction magnétique, observés à l’interface avec GdTiO₃ .Enfin, nous mettons en évidence la possibilité d’utiliser un paramètre de contrôle externe comme la lumière pour altérer le niveau de covalence dans les nickelates sans modifier la terre-rare. Ces résultats ouvrent la voie à de nouveaux dispositifs tirant partie du contrôle actif du niveau de covalence dans les isolants à transfert de charge
Transition metal oxides (Ti, Fe, Mn, Cu, etc.) display a multitude of features while crystallizing in a reduced number of structures. This is the case for example of perovskites which exhibit many electronic (insulators, metals, superconductors) and magnetic (ferro- and antiferromagnetic) orders. Their structural compatibility offers a unique playground for combining them in the search for new interfacial properties. A typical example discovered in 2004 is LaAlO₃ and SrTiO₃ whose interface reveals a high-mobility electron gas although the parent constituents are two conventional band insulators.Following-up on this major achievement, this thesis aims at generating new electronic interfacial phases, not from band insulators but rather from Mott and charge transfer insulators. At the interface between these types of compounds, band alignment is made more complex by the presence of strong correlations between electrons.Hence, interfacial reconstructions can destabilize the ground state, and generate new phases absent from the phase diagrams of the two building blocks.Initially, we synthetized, by pulsed laser deposition, a typical Mott insulator, rare earth titanates (RTiO₃ ) in the form of thin layers, which were optimized and characterized on different substrates.Secondly, we also grew charge transfer insulators, rare earth nickelates (RNiO₃ ). We specifically studied the effect of the ionic radius of the rare earth on the electronic structure of these compounds at low temperature.The core of this thesis is to study the interface formed by these two constituents via a combination of spectroscopic techniques (synchrotron radiation-based absorption, XAS, linear and circular dichroism XMCD and energy loss spectroscopy, STEM-EELS) in connection with ab-initio calculations.After demonstrating the emergence of a new ferromagnetic phase in nickelates, absent of the bulk phase diagram, we discuss in particular the role of correlations in nickelates on the charge transfer and magnetic reconstruction, observed at the interface with GdTiO₃ .Finally, we will propose a new external knob, light, to alter the level of covalence in nickelates without changing the rare earth. These results open the way for new devices taking advantage of the active control of the level of covalence in charge transfer insulators
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Wei, Haoming, Jose Luis Barzola-Quiquia, Chang Yang, Christian Patzig, Thomas Höche, Pablo Esquinazi, Marius Grundmann, and Michael Lorenz. "Charge transfer-induced magnetic exchange bias and electron localization in (111)- and (001)-oriented LaNiO3/LaMnO3 superlattices." American Institute of Physics, 2017. https://ul.qucosa.de/id/qucosa%3A23554.

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High-quality lattice-matched LaNiO3/LaMnO3 superlattices with monolayer terrace structure have been grown on both (111)- and (001)-oriented SrTiO3 substrates by pulsed laser deposition. In contrast to the previously reported experiments, a magnetic exchange bias is observed that reproducibly occurs in both (111)- and (001)-oriented superlattices with the thin single layers of 5 and 7 unit cells, respectively. The exchange bias is theoretically explained by charge transfer-induced magnetic moments at Ni atoms. Furthermore, magnetization data at low temperature suggest two magnetic phases in the superlattices, with Néel temperature around 10 K. Electrical transport measurements reveal a metal-insulator transition with strong localization of electrons in the superlattices with the thin LaNiO3 layers of 4 unit cells, in which the electrical transport is dominated by two-dimensional variable range hopping.
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Gati, Elena Aurelia [Verfasser], Michael [Akademischer Betreuer] [Gutachter] Lang, Jens [Gutachter] Müller, and Takahiko [Gutachter] Sasaki. "Thermodynamic studies of metal-insulator transitions in organic charge-transfer salts / Elena Aurelia Gati ; Gutachter: Michael Lang, Jens Müller, Takahiko Sasaki ; Betreuer: Michael Lang." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2017. http://d-nb.info/1135261431/34.

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Shaik, Sania. "Refrigeration Insulation Using Phase Change Material Incorporated Polyurethane Foam for Energy Savings." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1707283/.

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Incorporating insulation material with phase change materials (PCMs) could help enhance the insulation capability for a refrigerator system. The phase change material can absorb or release large amount of latent heat of fusion depending on surrounding temperatures for efficient thermal management. This research focuses on how incorporating PCM to the conventional PU foam insulation affects the inside temperatures of the refrigerator system and in-turn helps in conserving energy by reducing the compressor run time. It was found that only 0.25-inch-thick PCM layer in insulation can certainly benefit the refrigerators by reducing the amount of electricity consumption and thus increasing the total energy savings through the numerical study results via COMSOL Multiphysics in this study. This work aims to investigate a PCM-incorporated insulation material to accomplish the enhancement of thermal insulation performance for refrigerators.
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Breitenstein, Jacques. "Etude par spectroscopie raman de conducteurs organiques unidimensionnels, (tmtsf) 2x." Paris 7, 1988. http://www.theses.fr/1988PA077179.

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Trois sels de bechgaard (tmtsf)::(2)x (ou x=pf::(6), clo::(4) et reo::(4)) sont etudies dans des conditions de double resonance raman. Determination des modes de vibration donnant des termes importants dans ces conditions de double resonance. Mise en evidence de l'existence des modes rendus actifs grace a un forty couplage avec des transferts dynamiques de charge intermoleculaires ou intramoleculaires. Les informations importantes concernant ce couplage de modes internes - transferts de charge sont obtenues lors de l'etude de la transition metal - isolant et de la mise en ordre a 2k::(f) des anions dans (tmtsf)::(2)reo::(4). Observation des modes mettant en jeu des transferts intradimeres
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Balestrin, Lia Beraldo da Silveira 1991. "Triboeletrização : evidências da participação de reações mecanoquimicas." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250297.

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Orientador: Fernando Galembeck
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química
Made available in DSpace on 2018-08-27T09:01:49Z (GMT). No. of bitstreams: 1 Balestrin_LiaBeraldodaSilveira_M.pdf: 4255591 bytes, checksum: c4d0f9d5952dc35354bfb9f0d111643b (MD5) Previous issue date: 2015
Resumo: Quando dois materiais isolantes são atritados, ocorre a triboeletrização de suas superfícies, isto é, a formação de cargas estáticas, distribuídas em padrões fractais. Uma das hipóteses para explicar a eletrização de isolantes é a ocorrência de reações mecanoquímicas seguidas da transferência mútua de massa. Esta dissertação apresenta mapas de potencial elétrico de superfícies atritadas, que também foram examinadas por microscopia eletrônica de varredura (SEI, BEI) e microanálise EDX. Os resultados verificam a hipótese mecanoquímica associada à transferência de fragmentos poliméricos iônicos, sendo as reações iniciadas pela quebra de cadeias seguida da formação de várias espécies de alta energia e produtos de oxidação. Microanálises também detectaram a fixação de N2 nestas superfícies, evidenciando a participação da atmosfera e a formação de triboplasma. As imagens BEI revelam uma distribuição fractal de composição química consistente com a distribuição de fragmentos limitada por difusão, mas superior à dimensão fractal de distribuição de cargas. Esta diferença é atribuída à supressão de cargas devido a microdescargas elétricas desencadeadas por gradientes superiores à rigidez dielétrica do sólido ou do ar. As microdescargas diminuem os gradientes elétricos, mas, ao mesmo tempo, geram novas espécies muito reativas, aumentando a heterogeneidade química das superfícies. Essa dissertação descreve também alguns experimentos acerca da eletrização produzida por simples contato, obtendo-se padrões bem definidos com tempo de contato de 1 h, porém não revelam a transferência de fragmentos poliméricos mutuamente, sugerindo que o cisalhamento desempenhe um papel importante na transferência de fragmentos poliméricos eletrizados. Em um menor grau de aprofundamento, esta dissertação contempla outras consequências de cargas estáticas, como alterações no coeficiente de atrito
Abstract: Triboelectrification occurs when two insulators are rubbed, i.e. static charges are formed on the surface with a fractal distribution pattern. One of the hypotheses raised by the literature indicates that the electrification is accompanied by mutual mass transfer. This dissertation presents electric potential maps of rubbed surfaces, which were also examined by scanning electron microscopy (SEI, BEI) and EDX microanalysis. The results verify the hypothesis that the electrification is due to mechanochemical reactions associated with transfer of charged polymeric fragments. The reaction is initiated by breaking the chains, generating reactive species and oxidation products. Microanalysis also detected N2 fixation on these surfaces, evidencing the contribution of the atmosphere and the formation of triboplasma. The BEI images show a fractal distribution of chemical composition consistent with a fragment distribution limited by diffusion, but higher than the fractal dimension of the charge distribution. This difference is attributed to the suppression of charges due to electrical micro discharge triggered by gradients higher than the dielectric strength of solid or air. The micro discharges decrease electrical gradients, but at the same time, generates very reactive species further increasing the chemical heterogeneity of surfaces. This dissertation also describes some experiments about the electrification produced by single contact, resulting in well-defined patterns with a contact time of 1 h, but do not show the mutual transfer of polymeric fragments, suggesting that the shearing plays an important role in transferring electrified fragments. This work also includes other consequences of static charges, such as changes in the friction coefficient
Mestrado
Físico-Química
Mestra em Química
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Lefebvre, Stéphane. "Contribution à la caractérisation de l'IGBT en commutation à zéro de courant." Cachan, Ecole normale supérieure, 1994. http://www.theses.fr/1994DENS0009.

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Cette étude analyse la commutation de blocage d'un igbt utilise en commutation quasi-résonnante a zéro de courant. Deux igbt de structure technologique différente ont été étudiés, le premier est à base non homogène et a couche tampon, le second à base homogène et contrôlé d'injection de charges par l'émetteur. L'évolution de la charge stockée dans la base du transistor bipolaire interne au blocage est suivie et analysée à l'aide de simulations et d'expérimentations. Différents éléments interviennent sur l'évacuation de la charge stockée donc sur les pertes au blocage, qu'ils soient propres au composant (coefficients d'injection ou durées de vie) ou a sa commande (maintien du canal lors de la conduction de la diode antiparallèle). Ce qui permet de comprendre pourquoi les pertes au blocage sont plus faibles en commutation a zero de courant qu'en commutation commandée. Une caractérisation électrique et thermique de l'igbt permet ensuite de quantifier l'influence des conditions de commutation sur les pertes au blocage. Des limites de fonctionnement sont ainsi définies, pour s'affranchir de l'emballement thermique, principale cause de destruction des igbt a couche tampon en zcs a fréquence de découpage élevée
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Nauruzbayeva, Jamilya. "Mechanisms of Contact Electrification at Aluminum-Polytetrafluoroethylene and Polypropylene-Water." Thesis, 2017. http://hdl.handle.net/10754/623459.

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Contact electrification refers to the transfer of electrical charges between two surfaces, similar and dissimilar, as they are brought into contact and separated; this phenomenon is also known as static electrification or triboelectrification. For example, everyone has experienced weak electrical shocks from metal doorknobs, wool and synthetic clothing on dry days. While contact electrification might appear insignificant, it plays a key role in numerous natural and industrial processes, including atmospheric lightning, accumulation of dust on solar panels, charging of liquids during pipetting and flow in the tubes, and fire hazards in granular media. Contact electrification at metal-metal interfaces is well understood in terms of transfer of electrons, but a comprehensive understanding of contact electrification at interfaces of electrical insulators, such as air, water, polytetrafluoroethylene (PTFE), polypropylene remains incomplete. In fact, a variety of mechanisms responsible for transfer of electrical charges during mechanical rubbing, slipping, sliding, or flow at interfaces have been proposed via: electrons, ions, protons, hydroxide ions from water, specific orientation of dipoles, mechanoradicals, cryptoelectrons, and transfer of material. We have noticed that the extent of contact electrification of solids in water is influenced by surface free energies, mobile ions, surface roughness, duration of contact, sliding speeds, and relative humidity. Herein, we present results of our experimental investigation of contact electrification at the following interfaces: (i) PTFE-aluminum in air and (ii) polypropylene-water interfaces. To identify the underlying mechanism, we started with various hypotheses and exploited a variety of experimental techniques to falsify most of them until we got an answer; our techniques included high-voltage power supply (0-10,000 V), Faraday cages, Kelvin probe force microscopy, electrodeposition, X-ray photoelectron spectroscopy, energy-dispersive spectroscopy, optical microscopy, a contact angle cell, and high-speed imaging. We concluded that contact electrification at the PTFE-aluminum interface was driven by electrons transferred from aluminum to PTFE. In contrast, contact electrification at the polypropylene-water interface was driven by the specific adsorption of OH- ions onto polypropylene. These insights should be helpful in designing applications of polymers where electrical charging could have influence, or applications that could be based on electrical charging at such interfaces, such as triboelectric generator.
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Books on the topic "Charge transfer insulator"

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Launay, Jean-Pierre, and Michel Verdaguer. The moving electron: electrical properties. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198814597.003.0003.

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The three basic parameters controlling electron transfer are presented: electronic interaction, structural change and interelectronic repulsion. Then electron transfer in discrete molecular systems is considered, with cases of inter- and intramolecular transfers. The semi-classical (Marcus—Hush) and quantum models are developed, and the properties of mixed valence systems are described. Double exchange in magnetic mixed valence entities is introduced. Biological electron transfer in proteins is briefly presented. The conductivity in extended molecular solids (in particular organic conductors) is tackled starting from band theory, with examples such as KCP, polyacetylene and TTF-TCNQ. It is shown that electron–phonon interaction can change the geometrical structure and alter conductivity through Peierls distortion. Another important effect occurs in narrow-band systems where the interelectronic repulsion plays a leading role, for instance in Mott insulators.
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Book chapters on the topic "Charge transfer insulator"

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Takagi, H., H. Eisaki, S. Uchida, and R. J. Cava. "Charge Transport Properties of Strongly Correlated Metals near Charge Transfer Insulator to Metal Transition." In Spectroscopy of Mott Insulators and Correlated Metals, 185–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-57834-2_16.

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Mavroyannis, Constantine. "Charge Transfer Electron-Exciton Complexes in Insulators and Semiconductors." In Hydrogen in Disordered and Amorphous Solids, 119–26. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4899-2025-6_12.

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Mahmoud Waheeb, Omar. "Connect Two Crude Oil Distillation Units with One Crude Oil De-Salter in Dewania Refinery." In Crude Oil - New Technologies and Recent Approaches [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98182.

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Crude oil, which exported to refineries, already contains salt, water, and fouling crude oil received with salt content not less than 50 ppm. Dewania refinery with a capacity of 20,000 BPSD, which serves with two crude distillation units, each unit with a capacity of 10,000 BPSD, which operate without crude desalter. In an aim to reduce the effects of salts, water and, fouling associated with crude oil, two crude distillation units connected with one crude oil desalter with a capacity of 20,000 BPSD (one desalter). crude oil desalter transferred from (Daura Refinery) to Dewania refinery, in aim to reduce salt content from 50ppm to 5 ppm and mitigate water and other fouling. Crude oil desalter installed in the middle distance between two crude distillations units (90 m from each unit isometric piping). Crude oil, which is pumped by a charge pump to preheated in crude oil distillation unit with a train of heat exchangers. When the pipeline size increased from 4″ to 6″, which reduces the pressure dropped from 0.946 to 0.15 bar for each transfer pipeline and in consequence, the total pressure drop reduces from 11.011 to 10.215 bar for the whole unit. In an aim to reduce the heat dissipated from surface of transfer pipeline. Each transfer pipeline insulated with calcium silicate insulator, the thickness of insulator increased from 38mm to 50mm in an aim to reduce heat loss from −101.56 watts/m to −84.282 watts/m, which reduced temperature difference between the surface pipeline and environment from 13 to 10°C.
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Venkata Satya Siva Srikanth, Vadali. "Unique Surface Modifications on Diamond Thin Films." In Engineering Applications of Diamond. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98186.

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Diamond thin films are touted to be excellent in surface-sensitive sensing, electro-mechanical systems, and electrochemical applications. However, these applications often entail patterned active surfaces and subtle chemical surface modifications. But due to diamond’s intrinsic hardness and chemical inertness, surface patterning (using micro-machining and ion etching) and chemical surface modifications, respectively, are very difficult. In the case of surface patterning, it is even more challenging to obtain patterns during synthesis. In this chapter, the direct patterning of sub-wavelength features on diamond thin film surface using a femtosecond laser, rapid thermal annealing as a means to prepare the diamond thin film surface as an efficient direct charge transfer SERS substrate (in metal/insulator/semiconductor (MIS) configuration), and implantation of 14N+ ions into the surface and sub-surface regions for enhancing the electrical conductivity of diamond thin film to a certain depth (in MIS configuration) will be discussed encompassing the processing strategies and different post-processing characteristics.
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"Trap Property and Charge Transmission in PE." In Electrical Insulation Breakdown and Its Theory, Process, and Prevention, 129–55. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-8885-6.ch005.

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The electrical properties of the dielectric are achieved by affecting the charge transfer process. The trap characteristics have an important influence on the electrical properties of the dielectric by affecting the charge transfer process. Aggregation and trap level characteristics of nanographene on low density polyethylene (LDPE). The direct current conductivity, breakdown strength, trap level distribution, space charge distribution, and charge mobility of nanocomposites were investigated. The experimental results show that the interface region between graphene and polymer introduces many deep traps in the forbidden band of nanocomposites, which can reduce the trapping process of charge and inhibit the accumulation of space charge. This indicates that the addition of nanoscale graphene has a significant improvement in the electrical performance of high voltage DC cables, which will provide a reference for production and application.
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Du, Boxue. "Oil and Paper Insulation for DC Converter Transformer." In Research Anthology on Synthesis, Characterization, and Applications of Nanomaterials, 537–65. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-8591-7.ch024.

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Transformer oil and oil-impregnated paper, serve as the essential parts of converter transformer, suffering various electric fields. The accumulation of surface charge on the paper would lead to flashover. When the power flow of the HVDC system is reversed, the charge field will easily lead to discharge. Direct-fluorination is a method which could affect the material property without alternating the bulk property. Besides, a new type of nano-modified transformer oil is a method to improve properties. This chapter presents a study of the effect of fluorination on surface charge behavior, the effect of polarity reversal voltages on interface charge behavior and the effect of Boron nitride (BN) nanoparticles on the high thermal conductivity of transformer oil. Results show that fluorination had an influence on the chemical property of the paper and BN nanoparticles has improvements in heat transfer process. In the polarity reversal test, the dissipation rate becomes smaller as the reversal time gets longer.
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Walton, David J., and Fred J. Davis. "The synthesis of conducting polymers based on heterocyclic compounds." In Polymer Chemistry. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198503095.003.0011.

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Polymers are best known for their effectiveness as electrical insulators, indeed electrical wiring throughout the world is now sheathed in plastic. However, it was recognized early on that polymers with an appropriate structure ought to be able to conduct electricity. Unfortunately, the same features that might allow this phenomenon also introduce intractability and processing difficulties. As a consequence, it was not until the mid-1970s that the potential of these materials was explored and better-defined materials started to be made. There are now numerous polymers with substantial electrical conductivities and the topic of electrically conducting polymers still continues to excite with many hundreds of new publications printed each year. The backbone structures of some of conjugated polymers are given in Table 6.1. In this chapter we shall deal with electrochemical and chemical syntheses of some relatively simple examples. For electrical conductivity, it is necessary to transfer charge along a conjugated chain, between chains, and also along grain boundaries or between particles. The most energetically difficult process will control the rate of charge transport and this will vary with nature of the polymer, its physical form, and other parameters, but in all cases conjugation along the chain is necessary although it is not sufficient for carbonaceous polymers to simply possess a conjugated chain. To promote conductivity π-overlap along the entire polymer chain length is required to give a half-filled band of delocalized π -electrons. In real systems, distortions of the bonds disrupt the conjugation, and the materials are generally semiconductors. The higher metallic conduction can be achieved by a process known as doping in which electrons are added or more generally removed from the conjugated system (although this is not same as the doping process found in semiconductor technology) The simplest conjugated polymer chain is a polyacetylene chain. Such materials can be prepared by coordination polymerization, or using a sophisticated route involving the degradation of a soluble precursor polymer.
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Conference papers on the topic "Charge transfer insulator"

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Ko, Yeong-Uk, Keizo Yamada, Takeo Ushiki, and Robert Newcomb. "Modeling of substrate current measurement and charge transfer in insulators." In SPIE 31st International Symposium on Advanced Lithography, edited by Chas N. Archie. SPIE, 2006. http://dx.doi.org/10.1117/12.656491.

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An, Chen, Hui Wang, and Menglan Duan. "Analysis of Heat Transfer Performance for Deepwater Phase Change Material Sandwich Pipes." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95876.

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Abstract As the exploitation of oil and gas gradually enters the deep sea, the low-temperature and high-pressure deep-sea environment poses a huge challenge to the flow protection of pipelines (2014a). In this paper, the phase change material sandwich pipeline which uses phase change heat storage and exothermic to maintain the pipeline temperature is taken as the research object, the heat transfer characteristics of the deep-water phase change material sandwich pipe are studied through the combination of theoretical analysis and numerical simulation (2014b). The main contents include: Firstly, through the establishment of two-dimensional and three-dimensional pipe models, analyzed the temperature distribution along the pipeline and the radial temperature distribution of the pipeline under steady oil flow conditions. Secondly, by using transient heat transfer, the effects of phase change material parameters, the proportion of phase change material in the insulation layer, and the difference in the ratio of phase change materials in the insulation layer on the insulation performance are analyzed to obtain the best results. Insulation material and optimal insulation layer layout; finally, the thermal storage and the phase change conditions of the phase-change material sandwich pipe is studied under the re-starting condition. The results show that the effective holding time of the phase change material insulation layer is close to 1.4 times that the non-phase change material insulation layer, and the melting point size has little effect on the insulation material. The closer the phase change material is to the inner tube, the better the insulation effect. This study provide guidance for the design and utilization of phase change material sandwich pipe.
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Chang, Ruxia, Desong Fan, and Qiang Li. "Research on Thermal Properties of Insulator-Metal Transition at Room Temperature in Sm1-xCaxMnO3." In ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/mnhmt2019-3963.

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Abstract The high-purity electron-doped manganites Sm1-xCaxMnO3 nanopowder were prepared by the solid-state reaction method, then the bulk material were obtained through granulation, molding, calcining, grinding and polishing. SCMO nanoparticles with 200 nm were obtained by the sol-gal process. The phase and surface morphology of these materials were characterized by X-ray diffraction and Scanning electron microscope and other experiments. The variable resistivity of the bulk materials were measured by two-wire method in the temperature range of 100–420K. The thermal conductivity was measured by the Laser Flash method. The results show that different doping ratios can change the phase transition temperature of the metal-insulation state. The temperature changed from 0 to 50 °C. The TMI could be regulated to room temperature. When the temperature is high than the TMI, it performs as metal state, on the contrary, it performs as an insulating state.
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Fan, Jintu, and Xiaoyin Cheng. "A Numerical and Experimental Study of Heat and Moisture Transfer With Phase Change and Mobile Condensates in Fibrous Insulation." In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47597.

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This paper reports on an improved model of coupled heat and moisture transfer with phase change and mobile condensates in fibrous insulation. The new model considered the moisture movement induced by the partial water vapor pressure, a super saturation state in condensing region as well as the dynamic moisture absorption of fibrous materials and the movement of liquid condensates. The results of the new model were compared and found in good agreement with the experimental ones. Numerical simulation was carried using the model to investigate the effect of various material parameters on the transport phenomena.
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Alawadhi, Esam M. "Thermal Insulation Using Phase Change Material." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42549.

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This research studies the effectiveness of Phase Change Material (PCM) as a thermal insulation for a pipe. The objective of using PCM is to utilize its latent heat to minimize heat loss by absorbing heat loss from the pipe, which minimizes net heat loss from the pipe to the ambient. Finite element method is employed to solve the problem, and both conduction and natural convection of liquid PCM are considered as modes of heat transfer. The effectiveness of the PCM insulation is evaluated by comparing its thermal performance with insulation without phase change. The results indicate that the PCM is effective in reducing the heat loss from the pipe for low Rayleigh numbers condition. High resolution capturing of solid/liquid moving boundary, and the details of flow structure are presented.
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Al-Othmani, Mohamad, Nesreen Ghaddar, and Kamel Ghali. "Transient Human Thermal Comfort Response in Convective and Radiative Environments." In ASME 2008 Heat Transfer Summer Conference collocated with the Fluids Engineering, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/ht2008-56101.

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In this work, human transient thermal responses and comfort are studied in non-uniform radiant heating and convective heating environments. The focus was on a change from walking activity of human in outdoor cold environment at high clothing insulation to warm indoor environment at sedentary activity level associated with lower clothing insulation. A transient multi-segmented bioheat model sensitive to radiant asymmetry is used to compare how fast the human body approaches steady state thermal conditions in both radiative and convective warm environments. A space thermal model is integrated with the bioheat model to predict the transient changes in skin and core temperature of a person subject to change in metabolic rate and clothing insulation when entering conditioned indoor space. It was found that overall thermal comfort and neutrality were reached in 6.2 minutes in the radiative environment compared to 9.24 minutes in convective environment. The local thermal comfort of various body segments differed in their response to the convective system where it took more than 19 minutes for extremities to reach local comfort unlike the radiative system where thermal comfort was attained within 7 minutes.
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Krueckl, Viktor, and Klaus Richter. "Switching spin and charge between edge states in topological insulator constrictions: a transer matrix approach." In SPIE NanoScience + Engineering, edited by Henri-Jean Drouhin, Jean-Eric Wegrowe, and Manijeh Razeghi. SPIE, 2012. http://dx.doi.org/10.1117/12.931306.

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Knotts, Wesley, Danielle Miller, Changki Mo, Laura A. Schaefer, and William W. Clark. "Smart Insulation for Thermal Control in Buildings." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5007.

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Buildings are a significant source of energy consumption in the US and worldwide, and conditioning building interiors occupies a major portion of that expenditure. At the building level, a particular scenario can occur where it becomes more advantageous for a structure’s walls to be “open” to the outside, as opposed to remaining “closed”, in an insulating state. For instance, a cool night may follow a hot summer day after the sun sets, but traditional insulation captures heat built up inside a home. A clear, sunny day may also heat a building’s exterior during a cold winter day, and heat transfer to the interior would be more desirable than insulation. This paper presents a study of a concept, termed “smart insulation”, that could be used in such scenarios to take advantage of beneficial thermal gradients in order to save heating and cooling costs. Enabling heat transfer without moving air can also help control humidity within interior spaces, as well as limit noise either from moving air or through open windows. Unlike traditional insulation that maintains a specific insulating value during its useful life, smart insulation changes between an insulating and a conducting state depending on the thermal gradient. Some design concepts have been fabricated and were tested in an insulated chamber that provides a “hot side” and a “cool side”. In the test chamber, temperature measurements were taken and the insulating capacity of each design specimen was calculated. Results indicate that the designs have potential to operate between two states (with the best case ranging from 11% to 61% of a benchmark insulation case) and effectively provide sustainable heating or cooling by capitalizing on ambient outdoor conditions.
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Gross, Ulrich, and Khaled Raed. "Study on the Effective Thermal Conductivity of Macro, Mirco and Nano Porous Materials in the Light of the Knudsen Conduction/Radiation Coupling Effect." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22297.

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Thermal transport phenomena in porous media are characterized by conduction through solid matrix and filling gas, and also by radiation. The gas is dispersed in the porous system depending on the pore size distribution. In each pore, the gas contributes to the heat transfer between the pore surfaces. This effect is strongly influenced by pore size, gas atmosphere, accommodation coefficient and other factors. A recent publication of the present authors focused on modeling the change of the effective thermal conductivity when the gas atmosphere is changed. In the current contribution, the effect of pore size distribution on heat transfer in macro, micro, and nano insulation materials is presented. Samples were chosen from five different highly porous materials with different pore size distribution within the macro, micro, and nano classes. Porosity and pore size distribution of the samples were chosen to get a clear characterization of the materials. The effective thermal conductivity was measured by applying the radial heat flow method at temperatures up to 1000 °C. Evaluating Knudsen effect from the pore size distribution alone does not give plausible explanation for the measured thermal conductivity. However, it is important to consider the kind of connections between the pores. In case of nano materials, the radiation effect proves to be strongly dependent on the Knudsen number.
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Kushwaha, Sandeep Singh, and P. S. Ghoshdastidar. "Numerical Prediction of the Temperature Distribution Within a Human Eye During Laser Surgery." In ASME 2008 Heat Transfer Summer Conference collocated with the Fluids Engineering, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/ht2008-56259.

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In this paper a computational heat transfer model for prediction of the temperature distribution within the human eye during laser surgery is presented. The heat transfer within a tissue is described by the classic Pennes bioheat transfer equation. The intraocular temperature distribution is calculated using finite-difference method. Two types of computational domain have been considered: (i) rectangular parallelepiped and (ii) cylindrical. The eye is modeled as a composite layered structure consisting of four different ocular tissues, namely, cornea, aqueous, lens and vitreous. It is assumed that the eye is symmetrical about the pupillary axis. The absorption probability of ocular tissue is modulated based on the Lambert-Beer’s law to reproduce the exponential attenuation of the laser light with depth within a biomaterial. The heat flow is modeled as transient and three-dimensional for rectangular parallelepiped geometry and two-dimensional (axi-symmetric) for the cylindrical geometry. The results indicate that for the insulation condition imposed on the periphery of the eye the model based on rectangular parallelepiped geometry of the eye at no laser power and at the initial temperature of 25°C predicts temperature closer to in-vitro experimental measurements reported in literature whereas the model based on cylindrical geometry predicts higher temperature. The opposite is true (that is, lower temperature is predicted by the model based on cylindrical geometry) for high laser heat flux (2000 W/m2) and higher initial temperature (37°C). This study also presents changes in eye temperature subjected to intermittent laser source used in laser surgery techniques such as PRK and LASIK. A comparison of the results based on three different boundary conditions such as convection (hb = 10 W/m2K), constant temperature (37°C) and insulation on the eye periphery reveals that the model based on insulation condition predicts results closer to that of in-vitro experiment at no laser power and initial temperature of 25°C whereas at a laser power of 200 W/m2 and at the initial temperature of 37°C insulation boundary condition produces highest temperature followed by that produced by convection and constant temperature conditions. The heat transfer is one-dimensional for the insulated eye periphery whereas multi-dimensional heat flow takes place when the circumferential boundary condition is either convective or isothermal.
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