Phase domain boundary motion and memristance in gradient-doped FeRh nanopillars induced by spin injection

The B2-ordered alloy FeRh shows a metamagnetic phase transition, transforming from antiferromagnetic to ferromagnetic order at a temperature T t similar to 380K in bulk. In addition to temperature, the phase transition can be triggered by many means such as strain, chemical doping, or magnetic or electric fields. Its first-order nature means that phase coexistence is possible. Here, we show that a phase boundary in a 300-nm-diameter nanopillar, controlled by a doping gradient during film growth, is moved by an electrical current in the direction of electron flow. We attribute this to spin injection from one magnetically ordered phase region into the other driving the phase transition in a region just next to the phase boundary. The associated change in resistance of the nanopillar shows memristive properties, suggesting potential applications as memory cells or artificial synapses in neuromorphic computing schemes.

Automated summary

The B2-ordered alloy FeRh undergoes a metamagnetic phase transition at a critical temperature of around 380K, which can be triggered by various means. Research has shown that a phase boundary controlled by a doping gradient in a nano-pillar can be shifted by an electrical current, leading to memristive properties in resistive changes, suggesting potential applications in memory cells or artificial synapses in neuromorphic computing.