A half-metallic A- and B-site-ordered quadruple perovskite oxide CaCu3Fe2Re2O12 with large magnetization and a high transition temperature.
Strong correlation between spins and conduction electrons is key in spintronic materials and devices. A few ferro- or ferrimagnetic transition metal oxides such as La1-(x)Sr(x)MnO3, Fe3O4, CrO2 and Sr2FeMoO6 have spin-polarized conduction electrons at room temperature, but it is difficult to find other spin-polarized oxides with high Curie temperatures (well above room temperature) and large magnetizations for spintronics applications. Here we show that an A- and B-site-ordered quadruple perovskite oxide, CaCu3Fe2Re2O12, has spin-polarized conduction electrons and is ferrimagnetic up to 560 K. The couplings between the three magnetic cations lead to the high Curie temperature, a large saturation magnetization of 8.7 μB and a half-metallic electronic structure, in which only minority-spin bands cross the Fermi level, producing highly spin-polarized conduction electrons. Spin polarization is confirmed by an observed low-field magnetoresistance effect in a polycrystalline sample. Optimization of CaCu3Fe2Re2O12 and related quadruple perovskite phases is expected to produce a new family of useful spintronic materials.
1] Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan [2].
Wei-tin
WT
Chen
Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198, Japan.
Masaichiro
M
Mizumaki
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Hayato
H
Seki
1] Centre for Science at Extreme Conditions and School of Chemistry, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK [2].
Mark S
MS
Senn
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Takashi
T
Saito
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Daisuke
D
Kan
Centre for Science at Extreme Conditions and School of Chemistry, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK.
J Paul
JP
Attfield
1] Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan [2] Japan Science and Technology Agency, CREST, Uji, Kyoto 611-0011, Japan.
Yuichi
Y
Shimakawa