Correlation between crystallization behavior, electrical switching and local atomic structure of Ge–Te glasses

• Crystallization behavior of Ge–Te glasses
• Electrical switching studies on Ge–Te glasses and its applicability to phase change memory applications
• Electrical switching mechanism of Ge–Te glasses
• Close correlation between local atomic structure and physical properties of Ge–Te glasses

We report the results of the crystallization behavior, electrical switching and structure of the bulk GexTe100-x glasses to ascertain the role of composition on phase change behavior. Obtained quantities like crystallization temperature and switching parameters exhibit threshold behavior at x = 17 and 22. Within this compositional range, we find that measured properties are insensitive to x content and beyond this composition window it shows strong composition dependence and may be driven by the ordering among the structural units. The ordering of the glass molecular structure becomes maximized and shows anomalous behavior at x = 20 (xc). An effort has been made to understand the electrical switching characteristics and variation of threshold switching fields with Ge content on the basis of local atomic structure. The thickness dependence of switching fields and cyclability of these glasses identifies the mechanism of switching and influence of local atomic structure. The observed compositional variations are interpreted on the basis of the local atomic structure of the given glass and the corresponding crystalline phase.