Thermal Expansion of Willemite, Zn2SiO4

Abstract

The linear thermal expansion of a natural crystal of willemite (Zn2Si04) has been measured parallel and normal to the hexagonal axis from 2 to 1200 K. The linear coefficient a" is negative below 150 K and al is negative below room temperature. The Grtineisen parameter 'Y is about 0·5 at 1000 K and falls to less than - 1 below 60 K.