The stability of magnetooptic recording films based on rare earth - transition metal alloys has been investigated. Experimental results show two distinct degradation processes, one of which has been identified as oxidation of the active layer, the other of which appears to be a thermally activated relaxation of the microstructure. Performance data are presented for newly developed, stable structures which exhibit virtually unchanged 55-60 dB C/N ratios after annealing at 200 degrees centigrade in air. Environmental stability is discussed.
"Magnetooptic Quadrilayer Reliability And Performance", Proc. SPIE 0529, Optical Mass Data Storage I, (12 April 1985); doi: 10.1117/12.946426; https://doi.org/10.1117/12.946426