A Perovskite Containing Quadrivalent Iron as a Charge-Disproportionated Ferrimagnet


  • This work was partly supported by Grants-in-Aid for Scientific Research (grant nos. 19GS0207, 18350097, 17105002, 19014010, 19340098, 19052008) and by the MEXT Joint Project of Chemical Synthesis Core Research Institutions. I.Y. was financially supported by 21COE on the Kyoto Alliance for Chemistry The synchrotron radiation experiments were performed at the SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute.


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Ferri interesting: CaCuII3FeIV4O12, prepared at 15 GPa and 1300 K, undergoes a charge disproportionation (2 FeIV→FeIII+FeV) and electrical, magnetic, and structural changes at 210 K. The FeIIIO6 and FeVO6 octahedra are ordered in a rock-salt manner (see picture; Ca gray, O blue, Cu red), and the low-temperature phase has the ferrimagnetic structure CuII(S=1/2,↓)3FeIII(S=5/2,↑)2FeV(S=3/2,↑)2.