Preparation and dielectric properties of Al2O3-based ceramic composites with Sm2O3 and ZrO2 additives for terahertz applications

As Terahertz (THz) electromagnetic waves become significant for industrial applications, the choice and electrical characterization of materials play important roles in improving system efficiency. Due to their unique properties, ceramics have recently become increasingly explored for THz applications. To this end, the samples of Al₂O₃-based ceramic composites with Sm₂O₃ and ZrO₂ additives are prepared. The prepared ceramic composites are characterized utilizing THz time-domain spectroscopy (THz-TDS), a powerful analytical technique employing THz radiation. First, the impact of sintering temperature on the dielectric properties of the pure Al₂O₃ is examined. Thus, the sintering temperature is set at 1550 °C to fabricate the other composites. Moreover, the impact of ZrO₂, Sm₂O₃ and ZrO₂-Sm₂O₃ additives on the dielectric properties of Al₂O₃-based ceramic composites is examined. In this context, the refractive index, permittivity, absorption coefficient and loss tangent of Al₂O₃-based ceramic composites are studied. Accordingly, it is observed that the dielectric constant and refractive indices of composites containing ZrO₂, Sm₂O₃ and ZrO₂-Sm₂O₃ additives increase compared to the pure-Al₂O₃. Moreover, while the loss tangent decreases with Sm₂O₃ additives, ZrO₂, and ZrO₂-Sm₂O₃ additives cause a rise in the loss tangent. The presented results enable us not only to choose the proper composite but also to enhance the dielectric properties of Al₂O₃-based ceramics. Consequently, they pave the way for the use of Al₂O₃-based ceramic composites with Sm₂O₃ and ZrO₂ additives in a wide range of THz applications.