Thin film alloy mixtures for high speed phase change optical storage:: A study on (Ge1Sb2Te4)1-x(Sn1Bi2Te4)x

An approach is proposed to develop recording materials for high speed phase change optical data storage. It utilizes a thin film alloy mixture between a stoichiometric GeSbTe alloy and an additive ternary telluride alloy. Selection rules for an additive alloy are suggested. For a test, (Ge1Sb2Te4)(1-x)(Sn1Bi2Te4)(x) thin films are deposited by co-sputtering and their structural and thermal properties are studied. Ge1Sb2Te4 and Sn1Bi2Te4 are found to form a completely soluble pseudo-binary system, whose crystalline lattice parameters obey Vegard's rule over the entire range of x (0<x<1). Furthermore, the alloy mixtures display an increasing tendency for crystallization with Sn1Bi2Te4 content. Dynamic tests of disk samples are made to show the effectiveness of the approach for high speed erasure. (C) 2002 American Institute of Physics.