Domain wall patterning and giant response functions in ferrimagnetic spinels

TL;DR

This paper demonstrates that mechanically strained ferrimagnetic spinels exhibit stripe-like domain patterns that can be manipulated, which correlates with their large magnetoelastic and magnetodielectric responses, revealing new insights into magnetic domain control.

Contribution

It reveals the presence and manipulability of mesoscale magnetic domain patterns in ferrimagnetic spinels, linking these patterns to their giant response functions.

Findings

Stripe-like magnetic domain patterns observed below magnetostructural transitions.

Domain walls can be manipulated via magnetic field and mechanical stress.

Local and macroscopic measurements are directly correlated.

Abstract

The manipulation of mesoscale domain wall phenomena has emerged as a powerful strategy for designing ferroelectric responses in functional devices, but its full potential has not yet been realized in the field of magnetism. We show that mechanically strained samples of Mn$_3$O$_4$ and MnV$_2$O$_4$ exhibit a stripe-like patterning of the bulk magnetization below known magnetostructural transitions, similar to the structural domains reported in ferroelectric materials. Building off our previous magnetic force microscopy data, we use small angle neutron scattering to show that these patterns extend to the bulk, and demonstrate an ability to manipulate the domain walls via applied magnetic field and mechanical stress. We then connect these domains back to the anomalously large magnetoelastic and magnetodielectric response functions reported in these materials, directly correlating local and macroscopic measurements on the same crystals.