Fabrication and optical characterizations of hot-pressed transparent SrF2/Nd:SrF2/SrF2 composite ceramic

A novel transparent SrF2/Nd:SrF2/SrF2 composite ceramic with sandwich-like laminar configuration was designed and successfully fabricated by the hot-pressed sintering method. The composite ceramic possesses an apparent transition interfacial (about 200 μm in thickness) between SrF2 and Nd:SrF2 layers, formed by non-uniform distribution of raw powders and the diffusion of Nd ions during the high temperature sintering. The average grain sizes of SrF2 and Nd:SrF2 layers are about 262.1 μm and 28.6 μm, respectively. For a 2-mm thick transparent SrF2/Nd:SrF2/SrF2 composite ceramic hot-pressed at 900 °C for 2 h, the transmittance at 500 nm and 1200 nm are about 49.6 % and 62.3 %, respectively. The microstructure, emission spectra and thermal conductivities of ceramics are also detected and studied.