Magnetic Force Microcopy of the Magnetostructural Phases of Mn3O4

In this talk, we report temperature- and field- dependent magnetic force microscopy (MFM) studies of Mn3O4. The spinel Mn3O4 has novel phase structure at low temperatures due to a three-way competition between spin-orbital coupling, geometric frustration and external magnetic field. This competition could lead to complex magnetic pattern formations. A particularly interesting phase exists where the crystal lattice undergoes a transition to resolve the spin frustration due to internal and external magnetic fields. In this phase the spins were expected to be in a disordered state, but local magnetic ordering has not been explored in previous studies. We present results from our investigation of Mn3O4 phase space using a variable temeprature MFM. Measurements were made at temperatures between 4K and 75K and in magnetic fields up to 5 tesla.