Preparation of highly transparent mid-infrared MgF2 ceramics by low-pressure hot pressing

The co-precipitation approach was successfully used in this investigation to produce MgF 2 nanoparticles. The effects of various heat treatments on the particle size and morphology of MgF 2 nanoparticles were systematically investigated. Based on the experimental results, the powder calcined at 500 °C, having crystallites size that are typically between 80 and 120 nm in size, was identified as the optimal sample. This calcined powder was subsequently used to produce polycrystalline MgF 2 ceramics through hot pressing (HP). It was also investigated how the characteristics of MgF 2 ceramics were affected by low-pressure hot pressing. The results demonstrated that the optimal transmittance of 95.8 % was achieved at a pressure of 30 MPa and a hot-pressing temperature of 800 °C. Furthermore, the dielectric constant (ε r ), Q × f value, Vickers hardness ( H V ), and fracture toughness ( K IC ) of the samples produced at 30 MPa and 800 °C were evaluated. The dielectric constant and Q × f value of MgF 2 ceramics, measured at 13.6231 GHz, were found to be 5.2996 and 114534 GHz, respectively. The Vickers hardness was measured at 5.21 ± 0.42 GPa, and the fracture toughness was determined to be 0.842 ± 0.067 MPa m 1/2 .