Effects of Heat Treatment of ZnS Nanoparticles Prepared by Hydrothermal Synthesis on Microstructure and Optical Properties in Spark Plasma Sintering (SPS)

摘要

In this study we have investigated the effects of heat treatment of ZnS nanoparticles prepared by hydrothermal synthesis and commercial CVD method for comparison on microstructure and optical properties of spark plasma sintered (SPS) ZnS. The heat treatments of ZnS nanoparticles were carried out at 550℃ for 10 min. in a vacuum. According to heat treatment, the reactivity of ZnS nanoparticle surface decreased and pyrolysis phenomenon appeared, which were tentatively considered to affect the infrared transmittance of SPS sintered body. Also wurtzite phase may causes birefringence due to the optical anisotropy began to be produced in more than 950℃. Good optical properties of sintered ZnS were shown in 950℃ by SPS. When sintering with SPS method, it could be deteriorated in the optical properties by light scattering caused by the refractive index difference among ZnS, impurities (especially carbon originated from the graphite mold and punch), defects, and pores.