Thermal stability in CoFe/Os/OsMn films

A simple structure of Ta/CoFe/Os(d)/OsMn is deposited by HV sputtering system, where d varies from 0 to 2 nm. After deposition, all samples are subjected to magnetic field annealing at 1 kOe and at different temperatures for 30 minutes. No diffusion evidence is found from the Auger electron spectroscopy depth profile and magneto-optical Kerr effect measurements for samples with d=1 and 2 nm annealed below 300/spl deg/C. This result suggests that the inserted osmium layer prevents Mn diffusion into the magnetic CoFe layer.