High-Pressure Synthesis of SrCu3Mn4O12: A Room-Temperature Ferrimagnetic Semiconductor with Spin-Polarized Electronic Structure

Abstract

A-site-ordered quadruple perovskites (AA′3B4O12) exhibit rich electronic and magnetic behaviors arising from the coexistence of multiple transition-metal sublattices. Here we report the high-pressure synthesis and comprehensive characterization of SrCu3Mn4O12, a previously unknown Sr-based member of the A2+Cu3Mn4O12 family. X-ray diffraction and Rietveld refinement confirm a fully ordered Im3̅ structure. Magnetic measurements reveal room-temperature ferrimagnetism with a Curie temperature of approximately 325 K, together with semiconducting transport behavior and a large negative magnetoresistance of −38% under 7 T at 2 K. First-principles calculations further reveal a spin-polarized semiconducting state, in which the valence-band maximum and conduction-band minimum originate from opposite spin states. These results expand the A2+Cu3Mn4O12 family and establish SrCu3Mn4O12 as a promising ferrimagnetic semiconductor for spintronic and magnetoresistive applications.