Fabrication, microstructure and optical properties of Ce:SrF2 transparent ceramics

Abstract

Ce:SrF2 powders were synthesized via the co-precipitation method. These synthesized Ce:SrF2 powders were pure SrF2 phase with substitutions of Ce3+ for Sr2+. The average particle size of these powders was estimated to be less than 250 nm, and they also had high dispersibility. The calcination temperature of Ce:SrF2 powders had strong influence on the ceramic sintering properties. The ceramic microstructure became compact when increasing the calcination temperature from 100 °C to 400 °C, because of the gradual decrease in both the number and size of micro-pores. Ce:SrF2 transparent ceramics could be sintered at 910 °C for 2 h under 50 MPa with ceramic powders calcined at 300 °C and 400 °C, because the powders calcined at above 300 °C had nearly no crystal water. The highest in-line transmittance of 71% was obtained at 800 nm. The Ce:SrF2 transparent ceramic was found to have two absorption peaks at 248 nm and 289 nm, and two obvious emission peaks at 308 nm and 327 nm. If the transmittance in the UV range, 200–340 nm, could be effectively improved by reducing scattering centers, Ce:SrF2 transparent ceramic would be a promising direct-pumping solid state UV laser material.