Cation Distributions and Magnetic Properties of Ferrispinel MgFeMnO ₄

Abstract

The crystal structure and magnetic properties of the cubic spinel MgFeMnO₄ were studied by using a series of in-house techniques along with large-scale neutron diffraction and muon spin rotation spectroscopy in the temperature range between 1.5 and 500 K. The detailed crystal structure is successfully refined by using a cubic spinel structure described by the space group <i>Fd</i>3̅<i>m</i>. Cations within tetrahedral <i>A</i> and octahedral <i>B</i> sites of the spinel were found to be in a disordered state. The extracted fractional site occupancies confirm the presence of antisite defects, which are of importance for the electrochemical performance of MgFeMnO₄ and related battery materials. Neutron diffraction and muon spin spectroscopy reveal a ferrimagnetic order below <i>T</i>_C = 394.2 K, having a collinear spin arrangement with antiparallel spins at the <i>A</i> and <i>B</i> sites, respectively. Our findings provide new and improved understanding of the fundamental properties of the ferrispinel materials and of their potential applications within future spintronics and battery devices.