Annealing effect on the Fe/Pt multilayers grown on Al2O3 (0001) substrates

We studied the structure and magnetic properties of molecular-beam epitaxy grown 300 \Angstrom thick Fe/Pt multilayers with different bilayer thickness and annealing temperature. The Fe/Pt multilayers were deposited on 100 Angstrom thick Pt buffer layers at 100 degreesC on Al2O3 (0001) substrates. The structure of as-deposited Fe/Pt films was fcc(111). While the postannealing temperature greater than or equal to400 degreesC, an additional FePt(100) orientation was observed. A large coercivity range, namely, 200-16 000 Oe can be tuned by varying the bilayer thickness and annealing temperature. (C) 2004 American Institute of Physics.