Magnetization reversal and confinement effects across the metamagnetic phase transition in mesoscale FeRh structures

Abstract

The effects of mesoscale confinement on the metamagnetic behavior of lithographically patterned FeRh structures are investigated via Kerr microscopy. Combining the temperatureand field-dependent magnetization reversal of individual sub-micron FeRh structures provides specific phase-transition characteristics of single mesoscale objects. Relaxation of the epitaxial strain caused by patterning lowers the metamagnetic phase transition temperature by more than 15 K upon confining FeRh films below 500 nm in one lateral dimension. We also observe that the phase transition becomes highly asymmetric when comparing the cooling and heating cycles for 300 nm-wide FeRh structures. The investigation of FeRh under lateral confinement provides an interesting platform to explore emergent metamagnetic phenomena arising from the interplay of the structural, magnetic and electronic degrees of freedom at the mesoscopic length scale.