Study of the magnetic anisotropy in Ni/Cu and Ni/glass thin films

The magnetic properties of evaporated Ni/Cu and Ni/glass thin films have been investigated by means of the vibrating sample magnetometer (VSM), the Brillouin light scattering (BLS) and magnetic force microscopy (MFM). The Ni thickness, t, ranges from 31 to 165 nm. The second- and fourth-order magnetic anisotropy constants, K 1 and K 2, have been included; for the Ni/Cu series, K 1 was found to decrease from 1.0x106 to 0.18x106 erg/cm3 as t increases from 31 to 165 nm, while K 2 increased from 0.24x106 to 0.8x106 erg/cm3. Over all the thickness range, the magnetization easy axis is in plane. For thinner films, there is a good agreement between anisotropy constant values inferred from VSM and BLS. Stripe domains were observed for t≥165 nm in Ni/glass and t≥90 nm in Ni/Cu