은이 도핑된 칼슘 아연 인산염계 유리의 MgO 함량에 따른 구조, 화학적 및 기계적 특성 고찰

Abstract

In this study, a series of Ag2O doped calcium zinc phosphate glasses with systematically varied MgO/CaO ratios were synthesized via the conventional melt-quenching method and comprehensively characterized to evaluate their physical, thermal, mechanical, chemical, and structural properties. X-ray diffraction analysis confirmed the amorphous nature of all glass samples, as evidenced by the presence of broad diffraction halos and the absence of sharp crystalline peaks. Both the glass transition temperature and Vickers hardness exhibited a clear increasing trend with MgO concentration. This enhancement in thermal and mechanical properties is closely related to the higher field strength of Mg2+ ions relative to Ca2+, which leads to stronger ionic interactions with non-bridging and bridging oxygens. The increased field strength reinforces the phosphate network by promoting more rigid and energetically stable linkages, ultimately contributing to the formation of strong bonds and chemically durable glass structure. Chemical durability tests revealed a significant reduction in weight loss with higher MgO content, further supporting the improved network stability and resistance to aqueous degradation. These results suggest that Mg2+ ions, due to their higher field strength, play a more effective role than Ca2+ in enhancing network connectivity and suppressing depolymerization in the phosphate glass matrix. Structural characterization using Fourier-transform infrared spectroscopy demonstrated that the absorption band near 1270 cm-1, associated with asymmetric stretching vibrations of P=O bonds, systematically shifted to higher wavenumbers with increasing MgO content. This spectral evolution reflects progressive changes in the phosphate network connectivity and local bonding environment induced by Mg substitution, in agreement with the observed improvements in thermal and mechanical properties.