Study of the effect of the deposition rate and seed layers on structure and magnetic properties of magnetron sputtered FeNi films

• Fe19Ni81 films were prepared by magnetron sputtering with different deposition rate.
• The samples were deposited onto different seed layers (Cu, Cr, Ta, Ti).
• Ta/FeNi and Ti/FeNi films exhibit good texture and crystallinity.
• The increase of grain size leads to increase of angular anisotropy dispersion.

FeNi thin films were prepared by magnetron sputtering. A magnetic field of 250 Oe was applied during sample preparation parallel to the substrate surface in order to induce a uniaxial magnetic anisotropy. The film crystallinity and magnetic properties were studied as a function of the deposition rate and material of seed layer (Cu, Cr, Ta, Ti). Detailed analysis of the X-ray diffraction patterns shows no correlation between rate of deposition and grain size, which was deduced using Scherrer's formula. The Ta and Ti seed layers improve the structural features of FeNi films resulting in larger grain size and the development of a strong texture, both of which are favourable for particular sensor applications. Large grain size increases the angular dispersion of magnetic anisotropy.