Voltage controllable Pt/Co/AlO superparamagnetic films

Abstract Electrochemical reaction induced by gate voltage between metallic cobalt and cobalt oxides was found to remarkably reshape average volume of superparamagnetic particles in Pt/Co/AlOx stacks at room temperature and thus modulate superparamagnetic properties, such as saturation fields and saturated magnetization, of the superparamagnetic films. The interfacial reaction was indicated in anomalous Hall transport measurement. This voltage-controllable superparamagnetism observed in Pt/Co/AlOx films could be utilized in a new architecture of nonvolatile and high density magnetic random access memories or neuromorphic computing.