Abstract

Recently, there has been considerable interest in the properties of Co/Pd superlattices. Much of this interest stems from their proposed use as a high density magnetooptical recording medium: they possess enhanced Kerr effect at short wavelengths (~4000 A) relative to the currently used amorphous transition metal alloys. Large perpendicular anisotropies K can be obtained by combining thin Co layers (1-2 monolayers) with thicker Pd layers. This combination also produces saturation magnetizations M_s much smaller than that of pure Co, which leads to anisotropy fields (h_k = 2 K/M_s) much greater than the demagnetizing field 4πm_s, and, consequently, perpendicular hysteresis loops possessing squarenesses near 1. Finally, Pd layer thickness can be adjusted to place the Curie temperature at values appropriate for the available laser power.

© 1991 Optical Society of America