The effect of the Ni addition on the structure and magneto-optical (MO) pro
perties is investigated with (CoPt3)(1-x)Ni-x alloy films. The result shows
that, lower T-C and higher H-C could be simultaneously obtained in the Ni
range of 0.43 - 0.7. [111] > texture is not the only reason for perpendicul
ar magnetic anisotropy in the present system. Although Ni addition reduces
the Kerr rotation angle value in the blue-wave range, it slightly enhances
the value in the red-wave range. The films investigated can be considered a
s suitable for perpendicular magnetic recording applications if the proper
Ni addition range (0.43 - 0.5) is selected.