Sintering temperature driven structural and dielectric evolution of forsterite ceramics

Abstract This work reports the effect of sintering temperature (1400–1500 °C) on the structural, microstructural, and dielectric properties of forsterite (Mg 2 SiO 4 ) ceramics synthesized via a sol-gel method. X-ray diffraction confirmed the formation of phase-pure orthorhombic forsterite 1500 °C, while samples sintered at 1400 °C contained 2.3 wt% MgO. Microstructural analysis revealed a density increase from 78%–88% and a reduction in open porosity from 17% to 9% with increasing sintering temperature. Impedance spectroscopy analysis identified hopping conduction as the dominant mechanism, with DC activation energy decreasing from ~1.12 eV to ~0.96 eV as the sintering temperature increased from 1400 - 1500 °C. The ceramics exhibited a low-frequency dielectric constant (ε r ) that increased with temperature. The results demonstrated that a sintering temperature of 1500 °C is optimal for achieving high density (2.88 g/cm³), reduced electrical activation energy, and superior microstructural properties, crucial for advanced electronic applications.