Structural and magnetic properties of epitaxial Fe0.5Pd0.5 thin films studied by Mossbauer spectroscopy

The Mossbauer spectra of Fe0.5Pd0.5 thin films in a disordered, partially ordered and ordered L1(0) structure were analyzed on the basis of three main considerations. First, the hyperfine field acting on a resonant atom depends on the number of Fe in its first coordination sphere and this relation gives information on the homocoordination tendency in the alloy. Second, the uniaxial symmetry related to the chemical ordering induces a dipolar field: this contribution was evaluated in ordered face-centered-tetragonal (FCT) films. Third, the hyperfine field direction is in the film plane of a disordered sample, along the normal to the him plane in an ordered L1(0) structure and isotropic like in the magnetic domain walls. The contributions from disordered and ordered FCT Fe0.5Pd0.5, magnetic domain walls and small FCT iron rich clusters were clearly identified. (C) 1998 Elsevier Science B.V. All rights reserved.