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This work focuses on the effect of film thickness on the microstructural and magnetic properties of polycrystalline Fe80Ga20 films of different thickness (20 nm⩽t⩽200 nm) fabricated on Si(100) substrates. From x-ray diffraction, a <110> texture was normal to the film plane in all films. For all film thicknesses, the lattice constant perpendicular to the film plane was less than the bulk, and first decreased and then increased toward the bulk value with increasing t. From atomic force microscopy data, both surface roughness and grain size were found to increase with film thickness. Using the Villari effect, the effective magnetostriction constant λeff was measured. Using the Szymczak model, it was found that λbulk=91±5 ppm, close to the bulk isotropic polycrystalline value (λiso=98 ppm). The surface magnetostriction λs contribution to λeff was found to be -1065±271 ppm nm. It was found that the 20 nm thick film had weak uniaxial anisotropy, while all the other films were magnetically isotropic. An extension of Néel's model to saturation field showed that the experimental data obeyed this model and the surface term affected the effective saturation field (Hs eff) significantly. [ABSTRACT FROM AUTHOR]

The structural, magnetic, and magnetostrictive properties of 75 nm Fe100-xGax films (0≤x≤30) have been studied to determine how a forming field during growth affects these properties. Two film sets were grown using a cosputtering-evaporation technique with and without a forming field of 65 kA m-1. Using x-ray diffraction, the texture, lattice parameter, and the grain size were determined. An out-of-plane <110> texture was found for all films. The magnetization loops were measured on a magneto-optic Kerr effect magnetometer, from which the anisotropy symmetry was inferred from the remanent magnetization. It was found that the forming field produced a pronounced uniaxial anisotropy. The effective magnetostriction constant was measured using the Villari effect. The effective magnetostriction constant was compared with that calculated for a polycrystalline film with <110> out-of-plane texture using bulk constants, and the results are discussed. [ABSTRACT FROM AUTHOR]

Thin epitaxial Fe films grown on GaAs(100) and Ga0.8In0.2As(100) substrates were investigated to determine how tuning the lattice constant mismatch between the Fe and the substrate may change the in-plane anisotropies and the magnetostriction. Two sets of Fe films were grown using molecular-beam epitaxy, each capped with a Cr overlayer. For each film, the in-plane anisotropy constants were determined from the normalized magnetization loops measured using a magneto-optic Kerr effect magnetometer. The lattice mismatch was found to give no contribution to the in-plane anisotropies. For all the films the magnetostriction constants, determined by the Villari method, were negative and became more negative as the Fe thickness decreased. [ABSTRACT FROM AUTHOR]

A new deposition technique involving the dc magnetron sputtering of Fe simultaneously with Ga evaporation has been developed to fabricate thin Fe(1-x)Gax (0

The detailed analysis of atomic and magnetic structure has been performed by Mössbauer spectroscopy for polycrystalline Fe80Ga20 films of different thickness ranging from 20 nm to 200 nm. The films were deposited on Si(100) substrate using dual sputtering and evaporation method. Obtained CEMS spectra have been fitted with several Gaussian distributions of hyperfine magnetic field. The results point to the domination of BCC disordered A2 phase and the absence of DO3 and L12 phases in the films. Both hyperfine parameters and lattice constant reveal anomaly for 40 nm thick sample - presumably due to the change of the internal stress. Spin texture evolves from in-plane to out-of-the-plane configuration with increasing thickness. [ABSTRACT FROM AUTHOR]