L10-type Co100-xPtx single crystals in a single variant state were prepared by ordering under a compressive stress in order to determine accurately the uniaxial magnetocrystalline anisotropy constant KU. Both the lattice constants a and c increase with increasing Pt concentration, whereas the axial ratio c/a becomes minimum at x=50. The value of KU directly determined at 298 K exhibits a maximum value of 4.5 × 107 erg cm-3 for 50 at. % Pt. The second- and fourth-order anisotropy constants K1 and K2 determined by the Sucksmith-Thompson method become 4.1 and 0.6 × 10 7 erg cm-3, respectively. The value of K 1+K2 corresponding to the magnetocrystalline energy difference between the c and a axes becomes maximum at x = 50.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)