Densification and microstructure evolution of hot-pressed Er:SrF2 transparent ceramics

Erbium doped strontium fluoride (Er:SrF2) ceramics were fabricated by the hot-pressed (HP) sintering method without any sintering aids, and the densification and microstructure evolution of Er:SrF2 ceramics were investigated. The microstructure of Er:SrF2 ceramics was analyzed by SEM, and light scattering defects, including residual pores and un-dissolved ErF3 compound, were identified. The Er:SrF2 ceramic hot-pressed at 900 °C for 2 h exhibited the highest transmittance, and its transmittance at 500 nm and 1200 nm are 90.4% and 91.7%, respectively. In addition, it was clarified that the grain growth kinetic mechanism of Er:SrF2 ceramics at the final stage of sintering is related to the solute drag.