Preparation and properties of LiF transparent ceramics by cold sintering process

The development of optoelectronic devices depends on the development of optoelectronic materials such as transparent ceramics. LiF transparent ceramics are photoelectronic ceramics with excellent photoelectric properties. Still, the traditional preparation of LiF transparent ceramics generally needs a high temperature or high-pressure environment, and the cost is high. This paper adopts a cold sintering process to prepare high-density LiF transparent ceramics at low temperatures to reduce the preparation conditions. The effects of different cold sintering temperatures on microstructure, density, hardness, visible and near-infrared transmittance, and electrical properties of transparent ceramics were studied. The results show that using LiOH solution as the solvent, the relative density of LiF ceramics can reach up to 99.64% under the sintering condition of 375 °C/470 MPa, and the Vickers hardness is 1.34 GPa. Vickers hardness is 1.34 GPa. The transmittance in the visible and near-infrared regions is 60.45% and 85.31%, respectively. The dielectric constant and dielectric loss of 13 GHz are 4.36 and 1.11 × 10−3, respectively.