Investigation on the effect of reactive (CuO) and non-reactive (3YSZ) additives on dielectric and mechanical properties of MgTiO₃

The investigation in this study focused on the microstructure, mechanical strength, and microwave dielectric properties of novel MgTiO₃ composites containing different amounts of CuO and 3YSZ. The synthesis of the MgTiO₃ compound was carried out using the conventional solid-state reaction method, while the composites were fabricated through wet mixing, pressing in a die, and sintering in air at temperatures ranging from 1200 to 1350 °C for a duration of 5 h. Density measurements by Archimedes method, indicated that the addition of 3 wt% of both additives led to an improvement in the densification behavior of MgTiO₃. X-ray analysis of the sintered samples confirmed that the reaction between CuO and MgTiO₃ resulted in the formation of the Mg₂TiO₄ phase, while 3YSZ exhibited good chemical stability and acted as a secondary phase. The incorporation of CuO and 3YSZ effectively enhanced the mechanical properties of the MgTiO₃ ceramics. Specifically, the MgTiO₃ ceramics mixed with 1 wt% CuO and 5 wt% 3YSZ demonstrated excellent mechanical and dielectric properties, with a fractural strength (σ_b) of 90 and 70 MPa, Vickers hardness (HV) of 870 and 845, relative permittivity (ε_r) of 17.3 and 17.2, and quality factor (Q*f) of 174,000 and 166,000 GHz for 1 wt% CuO and 3 wt% YSZ, respectively.