Abstract

“The deepest and most interesting unsolved problem in solid state theory is probably the theory of the nature of glass and the glass transition.” [PW Anderson, Science 267 (1995) 1615]. This talk will focus on developments in understanding and exploiting the glassy state that is formed when a liquid is cooled into a solid state without crystallizing. We will consider such questions as the extent to which glasses should be considered to be disordered or ordered. Metallic glasses can show excellent mechanical properties — this leads to possible applications, but also opens up the possibility of using mechanical working to change the structure and properties of glass, something hardly explored for conventional oxide glasses. Chalcogenide glasses can show ultra-rapid crystallization and this is exploitable in computer memory. Focusing on metallic and chalcogenide systems, a variety of recent studies will be reviewed. An example is the recent discovery that there can be significant effects on the properties of a glass by mechanical loading even well within the (nominally) elastic regime. This contributes to the exploration of the range of energy that can be achieved in the glassy state, from very high (‘rejuvenated’) to very low (‘relaxed’ and even ‘ultrastable’).