High coercivity FePt thin films with Ag intermediate Layers deposited at 400°C

L1₀ phase FePt thin films deposited on amorphous Corning glasses and single crystal MgO (100) substrates were investigated. Epitaxial growth of the FePt [001] films was observed on MgO substrate at a deposition temperature of 400°C. With ultrathin Ag intermediate layers deposited between FePt layers, the film structure changed from interconnection network to isolated-island character. The perpendicular coercivity of the FePt film increased to about 32 kOe with intermediate layers inserted. The improvement of the magnetic properties may be attributed to the formation of island structures by the additive Ag layers in the FePt films.