Data recording layer based on selenium and or tellurium - and opt. other elements gives high signal to noise ratio and large gamma value

摘要

Recording layer comprises (a) >=30 pref. 30-100 atom % Se and/or Te, (b) In, Sn, Pb, P, As and/or S and opt. (c) Sb, Ga, Tl, ge and/or Si, the amt. of gp. (c) element(s) being 50 atom % of the total amt. of gp. (b) elements. Pref. the layer is 200-1000, esp. 300-800 angstroms thick. Recording can be carried out with high energy radiation e.g. laser or electron beams. The material has a high signal to noise ratio and large gamma value and is therefore suitable for recording video and/or audio information with high information density. An 800 angstroms Pb10Te90 film was produced on a glass plate by the vacuum vapour deposition process. An Ar laser (4880 angstroms, 40 mW output) was used for recording, with a point exposure time of 30 ns. Read-out was accomplished with a He-Ne laser (6328 angstroms 5 mW); It was found that the film had a high enough gamma value and the signal to noise ratio on reprodn. was 35 dB.