Cation Distributions and Magnetic Properties of Ferrispinel MgFeMnO.

The crystal structure and magnetic properties of the cubic spinel MgFeMnO 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 3̅. Cations within tetrahedral and octahedral 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 MgFeMnO and related battery materials. Neutron diffraction and muon spin spectroscopy reveal a ferrimagnetic order below = 394.2 K, having a collinear spin arrangement with antiparallel spins at the and 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.