Phase diagram analysis and crystal growth of solid solutions Ca_{1-x}Sr_xF_2

TL;DR

This study investigates the phase diagram of CaF2–SrF2, identifying an azeotropic point, and demonstrates the growth of large, homogeneous solid solution crystals near this composition using the Czochralski method.

Contribution

It provides detailed phase diagram data and demonstrates successful growth of large, homogeneous solid solution crystals of Ca_{1-x}Sr_xF_2 near the azeotropic composition.

Findings

Unlimited mutual solubility of CaF2 and SrF2.

Identification of the azeotropic point at 1373°C.

Successful growth of large homogeneous crystals up to 30 mm diameter.

Abstract

The binary phase diagram CaF$_2$--SrF$_2$ was investigated by differential thermal analysis (DTA). Both substances exhibit unlimited mutual solubility with an azeotropic point showing a minimum melting temperature of T_\mathrm{min}=1373^{\circ}$C for the composition Ca$_{0.582}$Sr$_{0.418}$F$_2$. Close to this composition, homogeneous single crystals up to 30 mm diameter without remarkable segregation could be grown by the Czochralski method.