Crystallization behaviour and magnetic properties of highly magnetostrictive Fe–Tb–Dy thin films

Abstract Thin films of the Fe–Tb–Dy alloy with compositions near to the Terfenol-D alloy (Fe 67 Tb 9 Dy 24 ) have been produced by ion-beam sputtering on sapphire substrates at room temperature. Mosaic and sintered targets have been used to vary the chemical composition of Fe, Tb and Dy. Additionally, 2 at% of the additive Zr has been used for some films. Polycrystalline films consisting mainly of the Fe 2 RE (RE=Tb, Dy) Laves phase could be obtained by subsequent heat treatment for all compositions investigated here. Measurements of the magnetostriction, the magnetic polarization and the Curie temperature combined with wide-angle X-ray diffraction (XRD) and wavelength dispersive X-ray analysis (WDX) allowed an interpretation of the crystallization behaviour. It has been found that Fe excess increases and rare earth excess decreases the crystallization temperature, whereas the addition of Zr leaves the crystallization temperature unaffected.