Impact of In2O3 content on the structural, thermal, and mechanical hallmarks of Na2O-BaO-ZnO-Fe2O3-P2O5 glass systems

Abstract

Five glass compositions of the form 20Na₂O–15BaO–10ZnO–(9–x)Fe₂O₃–xIn₂O₃–46P₂O₅, where 0 ≤ x ≤ 9.0 mol%, were synthesized using a traditional melting method under ambient conditions. In these glass systems, In₂O₃ was used to partially substitute Fe₂O₃. The impact of In₂O₃ content on the structural, thermal, and mechanical properties of the glasses were thoroughly investigated. Complete characterizations were carried out using XRD, DSC, and measurements of density and molar volume. Elastic parameters, including Poisson’s ratio, were also studied. The XRD patterns confirm the amorphous nature of the examined samples. The measured glass density increased linearly (3.57–3.83 g/cm³), while the calculated molar volume decreased linearly (34.48–34.11 cm³/mol). The DSC analysis indicates that indium ions predominantly occupy network-forming positions, enhancing the rigidity of the glass network. Additionally, as inferred from the DSC data, the thermo-physical parameters T_g, T_p, and glass stability (∆GS) increased almost proportionally as In₂O₃ content was added, while the heat capacity change (∆C_p) showed an inverse relationship. Regarding the mechanical properties, all elastic parameters decreased due to the compositional changes from In₂O₃/Fe₂O₃ modifications.