Growth of high optical quality zinc chalcogenides single crystals by solid phase recrystallization technique at barothermal treatment

The solid phase recrystallization (SPR) technique under a barothermal high-temperature gas-static pressing (HIP) treatment was implemented to the growth for ZnS and ZnSe single crystals. The application of 200 MPa isostatic pressure allowed increasing the process temperature up to 1150-1300 °C, which in turn has increased the rate of grain growth and reduced process duration to 8-52 h. The impurity contents in ZnS and ZnSe single crystals did not exceed 10−4 wt%. The obtained crystals demonstrated transmittance in the wide VIS-IR spectral range close to the theoretical, ranging in size from a few to tens mm, which allows their use in practical applications as a laser matrix.