Journal of Magnetism and Magnetic Materials ( IF 2.717 ) Pub Date : 2020-03-29 , DOI: 10.1016/j.jmmm.2020.166822 Zhiren Chen; Chunjiao Pan; Ning Wang; Mingxia Qiu; Tao Lin; Jing Liu; Shunpu Li; Peigang Han; Ji Shi; Kazuya Ando; Hongyu An
We study the perpendicular exchange bias (PEB) and spin-orbit torque (SOT) generation in the Pt/Co/MgO heterostructure by changing the thickness of the MgO layer. We show that the oxidation of the beneath Co layer increases with the MgO thickness. Strong PEB is obtained in the Pt/Co/MgO films, which exhibits a much higher blocking temperature compared with that in the Pt/Co/CoO films. Furthermore, it is found that the MgO thickness has significant effect on the SOT generation. Maximum values of the SOTs are obtained with a 0.8 nm-thick MgO layer, which decreases by increasing the MgO thickness from 0.8 to 1.6 nm. Our results shed a light on the essential role of the MgO layer in the heavy metal/ferromagnet/MgO heterostructure, a typical material system in spintronic devices, and provide a way to manipulate the magnetic properties and the SOTs by oxide layers.