The deterministic field-free magnetization switching of perpendicular ferrimagnetic Tb-Co alloy film induced by interfacial spin current

Abstract

Current-induced magnetization switching in compensated ferrimagnetic materials by the spin–orbit torque (SOT) effect is promising for the next generation information storage devices. In this work, we report the current-induced deterministic field-free magnetization switching of the perpendicular Tb-Co ferrimagnet layer in a Co/Ti/Tb-Co trilayers. We found that the switching proportion and polarity of the Tb-Co ferrimagnet depend on the magnetization direction of the in-plane Co layer. The switching process revealed by magneto-optical Kerr microscope imaging further confirmed the current-induced field-free switching of the Tb-Co layer. We also demonstrated the large SOT effective field and the perpendicular effective field acting on the Tb-Co layer, by utilizing the second harmonic voltage measurement and the current-induced loop shift method. The large interfacial SOT efficiency and deterministic field-free magnetization switching in the trilayers structure may accelerate the application of ferrimagnet in SOT memory devices.