Density Functional Theory Study of the Ionic Liquid [emim]OH and Complexes [emim]OH(H2O) n  (n=1,2)

Song, Zhi-Xiang; Wang, Haijun; Xing, Lijuan

doi:10.1007/s10953-009-9435-y

Cited by 36 publications

(22 citation statements)

References 36 publications

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“…A metodologia DFT pode ser aplicada a um conjunto muito diversificado de sistemas atômicos, moleculares, líquidos e sólidos, [27][28][29][30] e é um dos métodos teóricos mais utilizados atualmente. Podem-se encontrar excelentes textos de revisão sobre esta metodologia.…”

Section: Teoria Do Funcional Da Densidade (Dft)unclassified

Efeitos da adição de átomos de Mn na rede do GaN via métodos de estrutura eletrônica

Mazini¹,

Cavalheiro

Leite³

et al. 2010

Quím. Nova

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Recebido em 6/5/09; aceito em 9/11/09; publicado na web em 10/3/10 INDIRECT EFFECTS OF THE Mn INCORPORATION ON THE ELECTRONIC STRUCTURE OF NANOCRYSTALLINE GaN.A computational method to simulate the changes in the electronic structure of Ga 1-x Mn x N was performed in order to improve the understanding of the indirect contribution of Mn atoms. This periodic quantum-mechanical method is based on density functional theory at B3LYP level. The electronic structures are compared with experimental data of the absorption edge of the GaMnN. It was observed that the indirect influence of Mn through the structural parameters can account for the main part of the band gap variation for materials in the diluted regime (x<0.08), and is still significant for higher compositions (x~0.18).Keywords: GaN; diluted magnetic semiconductor (DMS); DFT. INTRODUÇÃOEstudos recentes mostraram que materiais como GaAs, InAs e GaN, dopados com quantidades de Mn, Fe, Ni, Co, 1-8 da ordem de 5% apresentam, além das propriedades semicondutoras, propriedades ferromagnéticas. 5,9 As propriedades magnéticas destes materiais estão associadas ao fato de que, nos metais de transição citados, os níveis d estão incompletos e apresentam geralmente um valor elevado de momento magnético. Isto confere aos materiais propriedades de semicondutor magnético diluído (DMS).Os DMSs são potenciais candidatos para utilização em spintrô-nica, tecnologia na qual os benefícios da carga e do spin do elétron se unem em um único dispositivo, 7 por possibilitarem a injeção de correntes elétricas com alto grau de polarização de spin entre um metal e um semicondutor que é observada em junções metal semicondutor tradicional.3,10-12 Os dispositivos spintrônicos baseados em DMSs apresentam potencial para promover a integração entre comunicação, memória e processamento em um único dispositivo proporcionando ganho extraordinário na velocidade de processamento de dados. 3,4,7,13 Outro benefício dos dispositivos spintrônicos reside na grande economia de energia, quando comparada aos dispositivos tradicionais. 5Entre os DMSs conhecidos o GaN dopado com Mn é um dos mais promissores candidatos a utilização em dispositivos spintrô-nicos, pois este material pode apresentar uma temperatura de Curie (Tc) acima da temperatura ambiente (Tc ~ 400 K). Em particular, materiais como Ga 1-x Mn x As e In 1-x Mn x As apresentam desvantagem de suas temperaturas de Curie encontrarem-se abaixo da temperatura ambiente, Tc ~ 100 K e Tc ~ 50 K, respectivamente, tornando-os menos convenientes para uso prático. 5,6,14 Outros materiais que também apresentaram propriedades ferromagnéticas à temperatura ambiente são o TiO 2 e ZnO, dopados com Mn, Fe e Co. [15][16][17][18] Para crescer filmes de Ga 1-x Mn x N (GaMnN) encontramos técni-cas como a Epitaxia por Feixe Molecular (MBE), a qual tem como principal característica o controle do crescimento dos filmes a nível de camadas atômicas, podendo produzir filmes monocristalinos com baixa densidade de defeitos. No entanto, para conseguir certas concentrações de Mn...

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Section: Teoria Do Funcional Da Densidade (Dft)unclassified

Efeitos da adição de átomos de Mn na rede do GaN via métodos de estrutura eletrônica

Mazini¹,

Cavalheiro

Leite³

et al. 2010

Quím. Nova

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“…Exploring the microscopic structures or behaviors of ILs in aqueous solution is challenging because it dictates macroscopic properties of mixtures. Various approaches have been employed to investigate the interaction between ILs and water including experimental techniques [6][7][8][9][10][11][12][13], as well as theoretical calculations [14][15][16] and molecular dynamics simulation [17][18][19][20][21]. Specially, NMR method has been frequently utilized to probe intra-and intermolecular interactions of ILs/water mixtures [21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Microscopic structures of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate in water probed by the relative chemical shift

Gao

Zhang

et al. 2010

Sci. China Chem.

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The relative chemical shifts () were put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF 4 ) during the dilution process with water. The concentration-dependent  (C2)H(C4)H ,  (C2)H(C5)H and  (C4)H(C5)H were analyzed. The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent. The strength of the H-bond between water and three aromatic protons follows the order: (C2)H···O > (C4)H···O > (C5)H···O. The concentration-dependent  (C6)H(C7)H and  (C6)H(C8)H indicate the formation of the H-bonds of (C alkyl )H···O is impossible, and more water is located around (C6)H than around (C7)H or (C8)H. The concentration-dependent  (C2)H(C4)H and  (C2)H(C5)H both increase rapidly when x water > 0.9 or so, suggesting the ionic pairs of EmimBF 4 are dissociated rapidly. The turning points of concentration-dependent  (C2)H(C4)H and  (C2)H(C5)H indicate that some physical properties of the EmimBF 4 /water mixtures also change at the corresponding concentration point. The microscopic structures of EmimBF 4 in water could be clearly detected by the relative chemical shifts.ionic liquids, 1 H NMR, microscopic structure, relative chemical shifts, 1-ethyl-3-methyl-imidazolium tetrafluoroborate

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“…Ab Initio DFT Calculations: All the calculations about binding energy, dipole moment, energy level, and geometry information were performed with the DFT using Gaussian 09 program with the B3LYP/6-311+G(d,p) basis set. [80][81][82][83] Configurations were optimized, and calculations were made at 0 K in vacuum.…”

Section: Methodsmentioning

confidence: 99%

Multi‐Foldable and Environmentally Stable All‐Solid‐State Supercapacitor Based on Hierarchical Nano‐Canyon Structured Ionic‐Gel Polymer Electrolyte

Lee

Song

et al. 2021

Adv Funct Materials

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New ionic-gel polymer electrolytes (IGPEs) are designed for use as electrolytes for all-solid-state supercapacitors (ASSSs) with excellent deformability and stability. The combination of the photochemical reactionbased polymer matrix, weak-binding lithium salt with ionic liquid, and ion dissociating solvator is employed to construct the nano-canyon structured IGPE with high ionic conductivity (σ DC = 1.2 mS cm −1 at 25 °C), high dielectric constant (ε s = 131), and even high mechanical robustness (bending deformation for 10 000 cycles with superior conductivity retention [≈91%]). This gives rise to ASSS with high compatibility and stability, which is compliant with foldable electronics. Consequently, this ASSS delivers remarkable electrochemical performance (specific capacitance of ≈105 F g −1 at 0.22 A g −1 , maximum energy density and power density of 23 and 17.2 kW kg −1 ), long lifetime (≈93% retention after 30 days), wider operating temperature (≈0-120 °C), and mechanical stabilities with no significant capacitance reduction after mechanical bending and multiple folding, confirming the superior electrochemical durability under serious deformation states. Therefore, this ultra-flexible and environmentally stable ASSS based on the IGPE having the nano-canyon morphology can be a novel approach for powering up the ultra-deformable and durable nextgeneration wearable energy storage devices.

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Density Functional Theory Study of the Ionic Liquid [emim]OH and Complexes [emim]OH(H2O) n (n=1,2)

Cited by 36 publications

References 36 publications

Efeitos da adição de átomos de Mn na rede do GaN via métodos de estrutura eletrônica

Efeitos da adição de átomos de Mn na rede do GaN via métodos de estrutura eletrônica

Microscopic structures of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate in water probed by the relative chemical shift

Multi‐Foldable and Environmentally Stable All‐Solid‐State Supercapacitor Based on Hierarchical Nano‐Canyon Structured Ionic‐Gel Polymer Electrolyte

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