Synthesis of ZrO2 doped BaO–TiO2–SiO2 (BTS) glass ceramics with enhanced mechanical, structural, morphological, tribological and dielectric properties for electronic applications

In this study, BaO–TiO₂–SiO₂ (BTS) glasses and glass–ceramics doped with ZrO₂, having the composition (30 − x)BaO•30TiO₂•40SiO₂•x[ZrO₂] (x = 0, 2, 4, and 6 mol%), were synthesized using the melt-quenching technique followed by sintering at 1000 °C for 4 h. Varying ZrO₂ content led to improved physical properties, including an increase in both the green (un-sintered) density (from 3.08 to 3.55 g/cm³) and sintered density (from 3.87 to 4.28 g/cm³). X-ray diffraction (XRD) analysis verified that the fabricated glasses exhibited an amorphous structure. Moreover, XRD analysis of the synthesized glass ceramics (GCs) revealed that higher ZrO₂ content and heat treatment facilitated the transition from an amorphous to a crystalline structure, with a dominance of primary phase of tetragonal Ba₂TiSi₂O₈ along with secondary phase of monoclinic ZrO₂. Furthermore, the fabricated GCs were characterized using FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), elemental mapping, a universal testing machine (UTM) for compression testing, hardness measurements, tribological evaluation, and impedance spectroscopy. FESEM analysis of all samples revealed a complex morphology with interconnected grains and a progressive reduction in residual glassy phases. Moreover, mechanical analysis showed significant improvements with rising ZrO₂ content, with BTSZC6 (x = 6 mol% ZrO₂) achieving a compressive strength of 604 MPa, fracture toughness of 41.59 MPa·m^1/2, and hardness of 866.2 HV. Moreover, tribological results showed that BTSZC6 had the lowest wear volume of 0.13 mm³ (10 N), while BTSZC2 (x = 2 mol% ZrO₂) recorded the lowest friction coefficient at 0.16 (10 N). Notably, the BTSZC6 sample exhibited an exceptional dielectric constant (⁓ 4704) with a low dielectric or tangent loss of about 0.09 at 10 Hz (500 °C), accredited to the space charge or interfacial polarization. These properties make the GCs promising candidates for the production of multilayer ceramic capacitors and electronics devices.