Control of domain wall patterning and anomalous response functions in ferrimagnetic spinels

The ferrimagnetic spinels Mn3O4 and MnV2O4 are known for their anomalous magnetoresponsive behaviors, including strong magnetoelastic and magnetodielectric couplings at low temperatures. At the same temperatures, crystals of these materials display a real-space separation of the volume into nanometer length-scale stripe domains, reminiscent of those in ferroelectrics. These stripe patterns demonstrate a remarkable sensitivity to environmental stress, and are controllable by applied fields. In this talk, we present new small angle neutron scattering and bulk data on single crystalline MnV2O4 which allow us to directly correlate anomalous inverse magnetoelastic and magnetocapacitance effects with the onset and field response of these mesoscale features. Neutron diffraction and small-angle X-ray scattering meanwhile reveal a strong intertwining of these effects with lattice degrees of freedom, collectively establishing strain as an important tuning parameter for anomalous behavior.