A neutron scattering study on a ferrimagnetic magnetocapacitance system Mn$_{3}$O$_{4}$

The low-temperature phase of the tetragonal Mn$_{3}$O$_{4}$ has long been known as a ferrimagnet with the Yafet-Kittel structure. The long-range ferrimagnetic order first develops at 41.2 K, upon cooling, and a commensurate cell-doubling magnetic order occurs along the $b$-axis at 32.7 K. Recently magnetocapacitance behaviors were observed in Mn$_{3}$O$_{4}$. We present our high-resolution neutron scattering data to show that Mn$_{3}$O$_{4}$ undergoes an additional lattice distortion around 25 K. Peak broadening of selected reflections suggests that the crystal structure becomes pseudo-orthorhombic at low temperatures. Relation between the lattice distortion and magnetism will also be discussed.