Improvement of thermal stability of exchange coupling in FeMn/NiFe films by Pt addition

An exchange coupling and thermal stability study in Fe(Pt)Mn/NiFe films has been investigated. When Pt atoms were added to an FeMn layer, most of the properties in the FeMn/NiFe films were improved. The resistivity increased with increasing Pt content. The exchange coupling field had a maximum value for a film with about 5-8 at. % Pt. Especially, it was found that the addi tion of Pt to the FeMn layer improved considerably the thermal stability of exchange coupling in the FeMn/NiFe films. In Fe39Pt6Mn55(7 nm)/NiFe(10 nm) films, an exchange coupling field of 100 Oe and a coercivity of 40 Oe were obtained after annealing at 300 degreesC. From the result of Auger analysi s, it was found that diffusion of the interface was suppressed by Pt additi on. (C) 2001 American Institute of Physics.