Large enhancement of ferromagnetism by Cr doping in Mn3O4 nanowires

Abstract

The Mn3O4 nanostructures having low temperature Curie point (45 K) disqualify them for most practical applications. In this work, single-crystalline Cr-doped Mn3O4 nanowires with ferromagnetic Curie point at room temperature (305 K) have been investigated. Our experimental results show an increase in effective magnetic moment per gram as Cr3+ replaces Mn3+ and oxygen vacancies, which result in a transition from paramagnetic (Mn3O4) to ferromagnetic. The doped Cr3+ and oxygen vacancies reveal the remarkable ferromagnetic in Mn3−xCrxO4 nanowires may be ascribed to bound magnetic polarons model. Our experimental results suggest these obtained nanowires are promising nanoscale building blocks in spintronic devices.