Combinatorial investigation of magnetostriction in Fe-Ga and Fe-Ga-Al

A high-throughput high-sensitivity optical technique for measuring magnetostriction of thin-film composition-spread samples has been developed. It determines the magnetostriction by measuring the induced deflection of micromachined cantilever unimorph samples. Magnetostriction measurements have been performed on as-deposited Fe-Ga and Fe-Ga-Al thin-film composition spreads. The thin-film Fe-Ga spreads display a similar compositional variation of magnetostriction as bulk. A previously undiscovered peak in magnetostriction at low Ga content was also observed and attributed to a maximum in the magnetocrystalline anisotropy. Magnetostrictive mapping of the Fe-Ga-Al ternary system reveals the possibility of substituting up to 8 at. % Al in Fe70Ga30 without significant degradation of magnetostriction. (C) 2008 American Institute of Physics.