Fabrication and magnetocrystalline anisotropy of NiCo(002) films

A series of 30-nm-thick epitaxial Ni_xCo_1-x (002) alloy films are fabricated by DC magnetron sputtering. MgO (002) and SrTiO₃ (002) single substrates are used for x>0.5 and x<0.5, respectively. The magnetocrystalline anisotropy of Ni_xCo_1-x (002) alloy films is studied in the entire composition region for 0≤x≤ 1.0. When x decreases, the cubic magnetic anisotropy constant K₁ changes sign from negative to positive at x=0.96 and becomes negative again at x= 0.79. It becomes more negative as x decreases from 0.79 to 0. The uniaxial anisotropy K_u is smaller than the K₁ by a factor of two orders.