Temperature dependence of growth morphology of sputtered (FePt/Pt) films on MgO(100) substrate

We have investigated growth morphology of FePt/Pt films prepared by sputtering on a MgO (100) substrate in a temperature range of 100-600 degreesC. The L1(0) ordered structure appeared at a low substrate temperature of 200 degreesC and became a dominant phase via a second-order type transformation. A transition of FePt film growth morphology from continuous two-dimensional (2D) layer-by-layer mode into 3D island growth mode was observed at a substrate temperature of about 400 degreesC. When the film grew in continuous mode the stress from lattice misfit played an important role in governing the growth morphology; while growing in island mode the thermal stress increasingly influenced it. The island structure revealed eightfold symmetry following the preferred process of elongating the channel length to broadening its width. (C) 2001 American Institute of Physics.