Thermal expansion of amorphous Zr65Al7.5Cu17.5Ni10 in the vicinity of the glass transition

The thermal expansion of non-crystalline Zr65Al7.5Cu17.5Ni10 has been studi ed in the range of the glass transition and in the undercooled liquid using a dilatometric device. The measuring technique used permits reliable exper imental results up to 40 K above the glass transition temperature. The line ar thermal expansion coefficient obtained is almost constant in the glassy state with a value of 8.0 x 10(-6) K-1. It discontinuously increases at the glass transition temperature yielding a value of 20.0 x 10(-6) K-1 in the undercooled liquid. The results are compared with specific heat measurement s of the amorphous material in this temperature range and are interpreted i n the framework of a cluster model.