The maximum of glass-forming ability in Se-GeSe 2 system - Phillips-Thorpe threshold and/or eutectic?

Abstract Glass-forming ability of Ge 0.08 Se 0.92 (eutectic composition) and Ge 0.20 Se 0.80 (Phillips-Thorpe threshold where the mean coordination number equals to 2.4) are compared employing very slow melts cooling. Using X-ray diffraction the presence of crystalline phase (Ge 4 Se 9 ) was found in slowly cooled melt of Ge 0.20 Se 0.80 . It is suggested that in Se-GeSe 2 system the maximum of glass-forming ability is shifted to the vicinity of the eutectic composition.