SPUTTERING OF DYFECO LAYERS WITH AN UNBALANCED MAGNETRON

DyFeCo films were d.c, sputtered from a magnetically unbalanced magnetron cathode. Their density, composition and magnetic properties were investigated systematically as a function of the sputter parameters pressure and power, and were compared with evaporated films. They exhibit a lower anisotropy constant and behave in terms of the ferrimagnetic properties like evaporated films with 5 at.% less transition metal content. Corresponding magneto-optical discs show a low recording performance. These effects are attributed to the bombardment of the growing layer with energetic particles during deposition, which probably leads to a precipitation of transition metal clusters in the amorphous matrix, possibly nanoscale superparamagnetic transition metal crystallites.