English
Related papers

Related papers: Local Structure of Thermoelectric Ca3Co4O9

200 papers

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 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

[Ca$_2$CoO$_3$]$_{0.62}$[CoO$_2$], a two dimensional misfit metallic compound, is famous for its rich phases accessed by temperature, $i.e.$ high temperature spin-state transition, metal-insulator transition (MIT) at intermediate…

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

We used fully correlated ab initio calculations to determine the effective parameters of Hubbard and t - J models for the thermoelectric misfit compound $\rm Ca_3Co_4O_9$. As for the $\rm Na_xCoO_2$ family the Fermi level orbitals are the…

Strongly Correlated Electrons · Physics 2015-05-28 Julien Soret , Marie-Bernadette Lepetit

The local structure of superconducting single crystals of K0.8Fe1.6+xSe2 with Tc = 32.6 K was studied by x-ray absorption spectroscopy. Near-edge spectra reveal that the average valence of Fe is 2+. The room temperature structure about the…

Superconductivity · Physics 2015-06-03 T. A. Tyson , T. Yu , S. J. Han , M. Croft , G. D. Gu , I. K. Dimitrov , Q. Li

A detailed reexamination of the (110) surface structure of rutile TiO2 has been carried out using first-principles total-energy methods. This investigation is in response to a recent high-precision LEED-IV measurement revealing certain…

Materials Science · Physics 2009-11-11 Scott J. Thompson , Steven P. Lewis

Neutron pair distribution function analysis and first principles calculations have been employed to study short-range correlations in heavily disordered dielectric material Sr$_x$Ba$_{1-x}$Nb$_2$O$_6$ ($x=0.35, 0.5$ and 0.61). The…

Perturbed angular correlation spectroscopy combined with $ab-initio$ electronic structure calculations is used to unravel the structural phase transition path from the low-temperature polar structure to the high-temperature structural phase…

We report an anomalous local structural response in the CuO2 planes associated with the appearance of charge inhomogeneities at low temperature in underdoped but superconducting La2-x(Sr,Ba)xCuO4. We used pair distribution function analysis…

Superconductivity · Physics 2007-05-23 M. Gutmann , E. S. Bozin , S. J. L. Billinge

We report on the crystallographic information such as lattice parameters, atomic positions, bond lengths and angles, and local crystalline distortion size and mode of single-crystal YCrO$_3$ compound by a high-resolution synchrotron X-ray…

Materials Science · Physics 2024-03-08 Qian Zhao , Si Wu , Yinghao Zhu , Junchao Xia , Hai-Feng Li

We have used high-resolution Extended X-ray Absorption Fine-Structure and diffraction techniques to measure the local structure of strained La$_{0.5}$Sr$_{0.5}$CoO$_3$ films under compression and tension. The lattice mismatch strain in…

Strongly Correlated Electrons · Physics 2009-11-13 C. K. Xie , J. I. Budnick , W. A. Hines , B. O. Wells , J. C. Woicik

We have investigated the electronic structure of A-site ordered CaCu$_3$Ti$_4$O$_{12}$ as a function of temperature by using angle-integrated and -resolved photoemission spectroscopies. Intrinsic changes of the electronic structure have…

Strongly Correlated Electrons · Physics 2019-06-13 H. J. Im , T. Sakurada , M. Tsunekawa , T. Watanabe , H. Miyazaki , S. Kimura

KCoO2 has been found in 1975 to exist in a unique structure with P4/nmm spacegroup with Co in a square pyramidal coordination with the Co atoms in the plane linked by O in a square arrangement reminiscent of the cuprates but its electronic…

Strongly Correlated Electrons · Physics 2024-02-20 Ozan Dernek , Santosh Kumar Radha , Jerome Jackson , Walter R. L. Lambrecht

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

The local atomic disorder and the electronic structure in the environment of manganese atoms in LaMnO_3 has been studied by x-ray absorption spectroscopy, over a temperature range (300K to 870K) covering the orbital ordering transition…

Strongly Correlated Electrons · Physics 2009-11-10 Raquel A. Souza , Narcizo M. Souza-Neto , Aline Y. Ramos , Helio C. N. Tolentino , Eduardo Granado

A complex magnetic order of the multiferroic compound Co3TeO6 has been revealed by neutron powder diffraction studies on ceramics and crushed single crystals. The compound adopts a monoclinic structure (s.g. C2/c) in the studied temperature…

Materials Science · Physics 2011-11-28 S. A. Ivanov , R. Tellgren , C. Ritter , P. Nordblad , R. Mathieu , G. Andre , N. V. Golubko , E. D. Politova , M. Weil

X-ray and neutron powder diffraction data as a function of temperature are analyzed for the colossal dielectric constant material CaCu3Ti4O12. The local structure is studied using atomic pair distribution function analysis. No evidence is…

Materials Science · Physics 2009-11-10 E. S. Bozin , V. Petkov , P. W. Barnes , P. M. Woodward , T. Vogt , S. D. Mahanti , S. J. L. Billinge

Pseudobinary heterostructural alloys of ZnO with MgO or CdO are studied by composing the system locally of clusters with varying ratio of cations. We investigate fourfold (wurtzite structure) and sixfold (rocksalt structure) coordination of…

Materials Science · Physics 2010-06-18 A. Schleife , M. Eisenacher , C. Rödl , F. Fuchs , J. Furthmüller , F. Bechstedt

A series of CaxCoO2 (0.15 <= x <= 0.40) materials have been prepared by means of ion exchange reaction from NaxCoO2. Transmission electron microscopy (TEM) measurements revealed a rich variety of structural phenomena resulting from cation…

Strongly Correlated Electrons · Physics 2009-11-11 H. X. Yang , Y. G. Shi , X. Liu , R. J. Xiao , H. F. Tian , J. Q. Li
‹ Prev 1 2 3 10 Next ›