Abstract
The magnetic properties of Co-0∼35at%Ir alloys of the perfect hcp crystal structure type were studied by means of a magnetic balance and a pendulum-type magnetometer, and the following results were obtained; The crystal magnetic anisotropy energies of hcp type Co–Ir alloys rapidly decreased with increase in Ir concentration. The magnetic moment \barμ per atom in these alloys decreased linearly with increase in Ir concentration, and the concentration dependence of \barμ, d\barμ⁄dq, in the hcp alloys was −2.59 μB/Ir, being lower in absolute value than −2.95 μB/Ir in fcc type Co–Ir alloys. If the magnetic moments of Co and Ir are constant for all compositions, the magnetic moment of Ir for the hcp Co–Ir alloys is −0.87 μB, and that for the fcc Co–Ir alloys is −1.20 μB.