The magnetic anisotropy of ordered equiatomic platinum cobalt

The magnetocrystalline anisotropy of a platinum 52 atomic % cobalt alloy has been measured at 298°K and 77°K. A single crystal of the tetragonal phase, with one predominant tetragonal orientation, has been shown to be strongly uniaxial with [001] as the easy direction. The anisotropy energy at 298°K can be represented by the equation E=K 0+K 1 sin2 Ψ, where K 0 is a constant, K 1 = 2·83 × 107 erg/cm3 and Ψ is the angle between the magnetization vector and the easy direction. It has also been shown that K 1 increases with the degree of long-range order but that the saturation magnetization decreases.