Critical role of W deposition condition on spin-orbit torque induced magnetization switching in nanoscale W/CoFeB/MgO

We study the spin-orbittorque induced magnetization switching in W/CoFeB/MgO heterostructures with Wdeposited under differentsputtering conditions. We show that the crystal structure andresistivity of W depend on the employedsputtering conditions. Switching current of nanoscale devices is smaller while effective anisotropy field is larger for the devices with moreresistive W channeldeposited at lowersputtering power and higher Ar gas pressure. The effective spin Hall angle evaluated from the switching probability varies by a factor of 2 –3 depending on the Wresistivity controlled by thesputtering conditions.
Source: Applied Physics Letters - Category: Physics Authors: Source Type: research