The effect of crystal structure of very thin hcp Co-Ni films on the initial magnetization curves and hysteresis loops

Abstract

Magnetic properties of thin films are strongly influenced by the orientation of the film. In this paper, thin (800 Å) hexagonal Co-Ni films with different textures were studied to understand the effect of film structure on the initial magnetization curves and hysteresis loops. It was found that films with [0002] texture had lower coercivity (∼100–250 Oe depending on grain size) and the energy required to saturate such samples was ∼2–4×106 ergs/cm3. Whereas films with [101̄1] texture had a coercivity of ∼700 Oe and energy required for saturation was ∼107 ergs/cm3. The hysteresis loss (energy of hysteresis) from these samples ranged from 0.6 to 3.5×107 ergs/cm3. It was found that the coercivity and hysteresis loss increases linearly with the magnetization energy. These results were consistent with the measurements on bulk single crystals where the energy required for saturation is smallest for basal plane samples.