High-Pressure Synthesis of Semiconducting PbCu3Mn4O12 with Near-Room-Temperature Ferrimagnetic Order.

ABSTRACT

A transition-metal oxide of PbCu3Mn4O12 was prepared at 1523 K and 10 GPa. An A-site-ordered quadruple perovskite structure with the space group Im3̅ is assigned for this compound. Based on bond-valence-sum calculations and X-ray absorption spectroscopy, the charge combination is determined to be PbCu32+Mn44+O12. Due to Cu2+(↑)-Mn4+(↓) antiferromagnetic coupling, a near-room-temperature ferrimagnetic phase transition is observed at approximately 287 K. PbCu3Mn4O12 exhibits a semiconducting electric transport property with the energy band gap Eg ≈ 0.2 eV. In addition, considerable low-field magnetoresistance effects are observed at lower temperatures. This study provides an intrinsic near-room-temperature ferrimagnetic semiconductor that exhibits potential applications in next-generation spintronic devices.