An effect of capping-layer material on interfacial anisotropy and thermal stability factor of MgO/CoFeB/Ta/CoFeB/MgO/capping-layer structure

摘要

We investigate the magnetic properties of a MgO/CoFeB/Ta/CoFeB/MgO/capping-layer (Ru or Ta) structure and properties of a magnetic tunnel junction with the structure as a free layer. By using Ru instead of Ta as the capping layer, interfacial anisotropy K-i increases by a factor of similar to 2 and a smaller damping constant is obtained. The increase in Ki results in an enhancement of the thermal stability factor of the free layer with the Ru capping layer compared with that with the Ta capping layer in magnetic tunnel junctions. Published by AIP Publishing.