THICKNESS VARIATION OF THE MAGNETOOPTICAL PROPERTIES OF TB,DY-FECO,PRTHIN-FILMS

The optimisation of magneto-optical data storage disk structures requi res a knowledge of the optical and magneto-optical constants of the st orage material. In this paper we present the optical (n + ik) and firs t order magneto-optical (Q(1) + Q(2)) constants for the rare earth-tra nsition metal alloys: Tb23.5Fe72.5Co4.5, (Tb23.5Fe72.5Co4.5)(89)Pr-11, Dy22Fe68.5Co9.5 and Dy28Fe52Co20. A combination of Kerr polarimetry a nd ellipsometry is used to evaluate these constants, which are then us ed to calculate the magneto-optic response as a function of magnetic l ayer thickness. A comparison between calculated and measured Kerr resp onses from both the air and substrate side of these structures reveals the self consistency of the modelling process and the validity of the determined constants.