Oxygen Dope in Layer Ordered Copper Perovskites.

Zhang-Rice physics and anomalous copper states in A-site ordered perovskites

In low dimensional cuprates several interesting phenomena, including high Tc superconductivity, are deeply connected to electron correlations on Cu and the presence of the Zhang-Rice (ZR) singlet state. Here, we report on direct spectroscopic observation of the ZR state responsible for the low-energy physical properties in two isostructural A-site ordered cuprate perovskites, CaCu(3)Co(4)O(12) ...

Strain effects on oxygen migration in perovskites.

Fast oxygen transport materials are necessary for a range of technologies, including efficient and cost-effective solid oxide fuel cells, gas separation membranes, oxygen sensors, chemical looping devices, and memristors. Strain is often proposed as a method to enhance the performance of oxygen transport materials, but the magnitude of its effect and its underlying mechanisms are not well-under...

Electronic Structure Study of Copper-containing Perovskites

Octahedral tilting in cation-ordered perovskites--a group-theoretical analysis.

Group-theoretical methods are used to enumerate the structures of ordered perovskites, in which 1:2 and 1:3 ordering of B and B' cations is considered in combination with the ubiquitous BX6 (or B'X6) octahedral tilting. The cation ordering on the B-cation site is described by irreducible representations of the Pm3 m space group of the cubic aristotype: Lambda1 (k = 1/3,1/3,1/3) for the cation o...

Infrared response of ordered polarons in layered perovskites.

We report on the infrared absorption spectra of three oxides where charged superlattices have been recently observed in diffraction experiments. In La 1.67 Sr 0.33 NiO 4 , polaron localization is found to suppress the low-energy conductivity through the opening of a gap and to split the E 2u-A 2u vibra-tional manifold of the oxygen octahedra. Similar effects are detected in Sr 1.5 La 0.5 MnO 4 ...