BaO/SrO/ZnO/SiO2 glass system: Influence of different nucleation agents

In the present study, detailed investigations on the crystallisation behaviour for the recently discovered Ba1-xSrxZn2Si2O7 phase were performed. This solid solution may possess zero to negative thermal expansion. In contrast to many other phases with negative thermal expansion, this phase can be crystallised from glasses and hence should be suitable for the preparation of cooking panels, telescope mirrors, and other mass production materials, where the thermal expansion properties have to be tailored exactly. Due to the high anisotropy of the phase, inducing volume crystallisation and reducing the crystal size is of main interest. The influence of ZrO2 and Pt as nucleating agents in the glass system BaO/SrO/ZnO/SiO2 was studied by calculating the Avrami parameter (n). The microstructure was investigated with scanning electron microscopy.