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Related papers: Electronic structure of the $\rm Ca_3Co_4O_9$ comp…

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The effects of electronic correlations and orbital degeneracy on thermoelectric properties are studied within the context of multi-orbital Hubbard models on different lattices. We use dynamical mean field theory with iterative perturbation…

Strongly Correlated Electrons · Physics 2015-06-16 Mehdi Kargarian , Gregory A. Fiete

We have performed both in-plane resistivity, Hall effect and specific heat measurements on the thermoelectric cobalt oxide Ca$_{3}$Co$_{4}$O$_{9}$. Four distinct transport regimes are found as a function of temperature, corresponding to a…

Strongly Correlated Electrons · Physics 2007-05-23 P. Limelette , V. Hardy , P. Auban-Senzier , D. Jerome , D. Flahaut , S. Hebert , R. Fresard , Ch. Simon , J. Noudem , A. Maignan

We used quantum chemical ab initio methods to determine the effective parameters of Hubbard and $t-J$ models for the $\rm Na_{x}CoO_2$ compounds (x=0 and 0.5). As for the superconducting compound we found the $a_{1g}$ cobalt orbitals above…

Strongly Correlated Electrons · Physics 2010-07-26 Sylvain Landron , Soret Julien , Marie-Bernadette Lepetit

We extracted, from strongly-correlated ab-initio calculations, a complete model for the chain subsystem of the $Sr_{0.4}Ca_{13.6}Cu_{24}O_{41}$ incommensurate compound. A second neighbor $t-J+V$ model has been determined as a function of…

Strongly Correlated Electrons · Physics 2009-11-10 Alain Gelle , Marie-Bernadette Lepetit

The layered misfit cobaltate Ca$_3$Co$_4$O$_9$, also known as Ca$_2$CoO$_3$[CoO$_2$]$_{1.62}$, is a promising p-type thermoelectric oxide. Employing density functional theory, we study its electronic structure and determine, on the basis of…

Materials Science · Physics 2017-06-13 Bin Amin , Ulrich Eckern , Udo Schwingenschlögl

A 59Co NMR study of CoO2, the x=0 end member of AxCoO2 (A = Na, Li...) cobaltates, reveals a metallic ground state, though with clear signs of strong electron correlations: low-energy spin fluctuations develop at wave vectors q different…

Strongly Correlated Electrons · Physics 2009-11-13 C. de Vaulx , M. -H. Julien , C. Berthier , S. Hebert , V. Pralong , A. Maignan

We use scanning tunneling microscopy to study the temperature evolution of electronic structure in Ca3Cu2O4Cl2 parent Mott insulator of cuprates. We find that the upper Hubbard band moves towards the Fermi energy with increasing…

Strongly Correlated Electrons · Physics 2021-12-28 Li Haiwei , Ye Shusen , Zhao Jianfa , Jin Changqing , Yayu Wang

Temperature dependent electrical resistivity, crystal structure and heat capacity measurements reveal a resistivity drop and metal to semiconductor transition corresponding to first order structural phase transition near 400 K in Ca3Co4O9.…

Materials Science · Physics 2012-04-17 Tao Wu , Trevor A. Tyson , Haiyan Chen , Jianming Bai , Hsin Wang , Cherno Jaye

We present the thermoelectric (TE) properties of LaCoO$_{3}$ compound in the temperature range 300-600 K. The experimental value of Seebeck coefficient ($\alpha$) at 300 K is found to be $\sim$635 $\mu$V/K. The value of $\alpha$ decreases…

Strongly Correlated Electrons · Physics 2017-04-25 Saurabh Singh , Sudhir K. Pandey

Electronic structure calculations using the augmented spherical wave method have been performed for CuRhO2. For this semiconductor crystallizing in the delafossite structure, it is found that the valence band maximum is mainly due to the 4d…

Strongly Correlated Electrons · Physics 2009-09-03 Antoine Maignan , Volker Eyert , Christine Martin , Stefan Kremer , Raymond Fresard , Denis Pelloquin

The electronic structure of Na$_x$CoO$_2$ revealed by recent photoemission experiments shows important deviations from band theory predictions. The six small Fermi surface pockets predicted by LDA calculations have not been observed as the…

Strongly Correlated Electrons · Physics 2007-05-23 Sen Zhou , Meng Gao , Hong Ding , Patrick A. Lee , Ziqiang Wang

Structural, impedance, ferroelectric and magnetic properties were examined in multiferroic Bi_{2}Fe_{4(1-x)}Co_{4x}O_{9} (0$\leq$x$\leq$0.02) ceramics synthesized via solid-state reaction method. X-ray diffraction analysis and Rietveld…

Materials Science · Physics 2016-05-06 S. R. Mohapatra , B. Sahu , M. Chandrasekhar , P. Kumar , S. D. Kaushik , S. Rath , A. K. Singh

The temperature-dependent electronic structures of heavy fermion compound CeB$_{6}$ are investigated thoroughly by means of the combination of density functional theory and single-site dynamical mean-field theory. The band structure,…

Strongly Correlated Electrons · Physics 2017-05-03 Haiyan Lu , Li Huang

The doping and temperature dependent optical conductivity spectra of the quasi-two-dimensional Ca_{2-x}Sr_xRuO_4 (0.0=<x=<2.0) system were investigated. In the Mott insulating state, two electron correlation-induced peaks were observed…

Strongly Correlated Electrons · Physics 2009-11-07 J. S. Lee , Y. S. Lee , T. W. Noh , S. -J. Oh , Jaejun Yu , S. Nakatsuji , H. Fukazawa , Y. Maeno

We investigate the detailed electronic structure of PrCoO$_3$ and its temperature evolution using state-of-the-art photoemission spectroscopy and ab initio band structure calculations. We observe that in addition to the correlation effect,…

Strongly Correlated Electrons · Physics 2009-11-13 S. K. Pandey , Swapnil Patil , V. R. R. Medicherla , R. S. Singh , Kalobaran Maiti

The presence of complexity in the electronic structure of strongly correlated electron system NdCoO$_3$ (NCO) have sparked interest in the investigation of its physical properties. Here, we study the the Seebeck coefficient ($\alpha $) of…

Materials Science · Physics 2023-12-19 Abhishek Pandey , Sudhir K. Pandey

The fascinating electronic properties of the family of layered organic molecular crystals kappa-(BEDT-TTF)2X where X is an anion (e.g., X=I3, Cu[N(CN)2]Br, Cu(SCN)2) are reviewed. These materials are particularly interesting because of…

Strongly Correlated Electrons · Physics 2007-05-23 Ross H. McKenzie

We show that important anomalous features of the normal-state thermoelectric power S of high-Tc materials can be understood as being caused by doping dependent short-range antiferromagnetic correlations. The theory is based on the…

Strongly Correlated Electrons · Physics 2009-10-30 G. Hildebrand , T. J. Hagenaars , W. Hanke , S. Grabowski , J. Schmalian

We use the coupled 2d-spin-3d-fermion model proposed by Rosch {\sl et. al.} (Phys. Rev. Lett. {\bf 79}, 159 (1997)) to study the thermoelectric behaviour of a heavy fermion compound when it is close to an antiferromagnetic quantum critical…

Strongly Correlated Electrons · Physics 2009-11-07 Indranil Paul , Gabriel Kotliar

We found a new cobalt oxide (CaOH)1.14CoO2 by utilizing the high-pressure technique. X-ray and electron diffraction studies revealed that the compound has layer structure which consists of CdI2-type CoO2 layers and rock-salt-type double…

Materials Science · Physics 2007-05-23 M. Shizuya , M. Isobe , Y. Baba , T. Nagai , M. Osada , K. Kosuda , S. Takenouchi , Y. Matsui , E. Takayama-Muromachi
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