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Carbon dioxide; Cobalt compounds; Dichroism; Ferrimagnetism; Lanthanum compounds; Perovskite; Rhenium compounds; X ray absorption spectroscopy, Bond-valence sum; Conducting band; Degree of order; First principle calculations; Magnetoresistance effects; Perovskite oxides; Spin couplings; X-ray magnetic circular dichroism, Copper compounds
Abstract:
An A-and B-site ordered quadruple perovskite oxide LaCu3Co2Re2O12 was synthesized at 9 GPa and 1323 K. The compound possesses a Pn-3 space group, where both A and B sites are orderly occupied by different cations with a nearly 100 degree of order. Bond valence sum calculations and x-ray absorption spectroscopy confirm the charge distribution to be LaCu2+3Co2+2Re5.5+2O12. A ferrimagnetic phase transition is found to occur around 150 K due to the Cu2+(â )-Co2+(â )-Re5.5+(â ") spin coupling found by x-ray magnetic circular dichroism at Cu-, Co-, and Re-L2,3 edges. The magnetoresistance effects as well as the first-principle calculations indicate the half-metallic nature for LaCu3Co2Re2O12 with a wider energy gap at the up-spin channel and a conducting band at the down-spin channel. © 2020 Author(s).
