Mössbauer spectroscopic study has been conducted on a spinel oxide MnV2O4 by using a 1mol% 57Fe-substituted polycrystalline specimen as an absorber. The substituted 57Fe ions occupy both the A- and B-sites as Fe2+ and Fe3+ with a high-spin state, respectively. The Mössbauer spectra clarify the local crystallographic structure and the magnetic structure of both the Mn2+ ion at the A site and the V3+ ion at the B site. The spectra in the magnetically ordered phase were analyzed using a mixed magnetic and quadrupole Hamiltonian, and the magnetic structures were obtained by calculating the electric field gradient (EFG) axes with respect to the crystallographic axes. Below Tc ∼ 60K, a ferrimagnetic order along the 〈001〉c axis was observed in the cubic phase, whereas below Ts ∼ 50K, a simultaneous transition into a tetragonal phase and a canted ferrimagnetic state were observed. In this tetragonal phase, the V3+ spins were found to be almost within the tetragonal ð110 Þt [cubic (100)c] plain and inclined by 52° from the c-axis, while the Mn2+ spins were found to be along the c-axis opposite to the V3+ spins.
ASJC Scopus subject areas
- Physics and Astronomy(all)