Ce3+ emission in hexagonal and orthorhombic phases of CaSO4

CaSO4 exists in several phases. The most common phase of CaSO4 is orthorhombic and reported Ce3+ emission corresponds to this phase. However, significant change in the emission of Ce3+ is observed when CaSO4 crystallizes in hexagonal phases. The emission is observed at 354 nm as compared to the spilt band at 305 and 326 nm for the orthorhombic phase. The preparation procedure and photoluminescence spectra for orthorhombic and hexagonal phases are described in this paper.