Ultrathin permalloy films

In view of the principle of glow-discharge, ultrathin Ni₈₁Fe₁₉(12 nm) films were prepared at an ultrahigh base vacuum. The anisotropic magnetoresistance coefficient (ΔR/R %) for Ni81Fe₁₉(12 nm) film reaches 1.2%, while the value of its coercivity is 127 A/m (i.e. 1.6 Oe). Ultrathin Ni₈₁Fe₁₉(12 nm) films were also prepared at a lower base vacuum. The comparison of the structure for two kinds of films shows that the films prepared at an ultrahigh base vacuum have a smoother surface, a denser structure with a few defects; the films prepared at a lower base vacuum have a rougher surface, a porouser structure with some defects.