Large Low-Field Magnetoresistance in Perovskite-typeCaCu3Mn4O12without D

Direct observation of the ferrimagnetic coupling ofA-site Cu andB-site Fe spins in charge-disproportionated CaCu3FeMizumaki1, Chen2, Saito3 et al. 2011Phys. Rev. B442220View full textAdd to dashboardCite

“…Although the two Fe sites, i.e., chargedisproportionated Fe 3+ and Fe 5+ , were distinguished in the neutron structure analysis, the corresponding two components in the spectra were not evident. Because the 3d levels in Fe are very close to the 2p levels in oxygen so that the electronic structures of Fe 3+ and Fe 5+ may be considered as 3d 5 and 3d 5 L 2 (where L is a ligand hole), respectively, the XAS spectra for Fe 3+ and Fe 5+ should be quite similar. Thus, the observed spectra represent the average electronic structure for Fe 3+ and Fe 5+ .…”

Magnetic coupling betweenA′andBsites in theA-site-ordered perovskiteSaito1, Chen2, Mizumaki3 et al. 2010Phys. Rev. B20360View full textAdd to dashboardCite

“…This is mainly because TM ions are too small to be stabilized at the usually 12-fold A site. However, particular types of distortions in the BO 6 octahedron network produce quasisquare-planar coordination at some part of the A sites that can incorporate JahnTeller ͑JT͒ active TM ions. 1 An example of such an A-site-ordered perovskite is AAЈ 3 B 4 O 12 , in which 3/4 of the A sites in an ABO 3 perovskite ͑denoted as the AЈ site͒ are occupied by JT ions such as Cu 2+ and Mn 3+ , with a 2a 0 ϫ 2a 0 ϫ 2a 0 cubic unit cell of Im-3 symmetry ͑a 0 : lattice constant of the perovskite prototype͒, as illustrated in Fig.…”

A half-metallic A- and B-site-ordered quadruple perovskite oxide CaCu3Fe2Re2O12 with large magnetization and a high transition temperature

“…The A-and B-site-ordered quadruple perovskite-structure oxide is derived from the A-site-ordered perovskite with general formula AA [31][32][33] . In the present study we prepared an AA (10 GPa) and high temperature (1400 K), as described in Methods.…”