CaCu3Mn2Te2O12: An Intrinsic Ferrimagnetic Insulator Prepared Under High Pressure

Abstract

CaCu₃Mn₂Te₂O₁₂ was synthesized using high-temperature and high-pressure conditions. The compound possesses an A- and B site ordered quadruple perovskite structure in Pn3̅ symmetry with the charge combination of CaCu₃²⁺Mn₂²⁺Te₂⁶⁺O₁₂. A ferrimagnetic phase transition originating from the antiferromagnetic interaction between A' site Cu²⁺ and B site Mn²⁺ ions is found to occur at T_C ≈ 100 K. CaCu₃Mn₂Te₂O₁₂ also shows insulating electric conductivity. Optical measurement demonstrates the energy bandgap to be about 1.9 eV, in agreement with the high B site degree of chemical order between Mn²⁺ and Te⁶⁺. The first-principles theoretical calculations confirm the Cu²⁺(↓)-Mn²⁺(↑) ferrimagnetic coupling as well as the insulating nature with an up-spin direct bandgap. The current CaCu₃Mn₂Te₂O₁₂ provides an intriguing example of an intrinsic ferrimagnetic insulator with promising applications in advanced spintronic devices.