Effect of growth parameters on the structure and magnetic properties of thin polycrystalline Fe films fabricated on Si〈1 0 0〉 substrates

Abstract This paper deals with the experimental investigation of the structure and magnetic properties of thin polycrystalline Fe films. Two sets of 50 ± 2 nm thick Fe films were fabricated on Si〈1 0 0〉 substrates with native oxides in place by varying (i) the sputter pressure p Ar and (ii) the Fe sputter power P Fe . X-ray diffraction (XRD) study revealed that all films grew with strong 〈1 1 0〉 texture normal to the film plane. No higher order peaks were observed in any of the films studied. For both film sets, the lattice constant ( a ) was less than the bulk Fe lattice constant ( a 0  = 2.866 A), which suggested the existence of compressive strain in all films. Two regions of homogeneous strain were observed over the range of p Ar studied. Magneto-optical Kerr effect (MOKE) measurements showed that all films exhibited magnetically isotropic behaviour. The magnetic properties were observed to be influenced strongly by p Ar . The film grown at p Ar  = 4 μbar was the most softest ( H s  = 100 ± 8 kA m −1 , M r / M s  = 0.87 ± 0.02) film among all the films studied. The magnetic properties were found to be independent of P Fe . The effective saturation magnetostriction constant λ eff determined (using the Villari method) was positive (4 ± 1 ppm) and observed to vary within the calculated error.