Effect of mixed rare earth cations on structure, optical, mechanical and radiation shielding parameters of Na2O–B2O3 glass

Abstract

The value of rare earth-containing glasses continues to increase, resulting in a higher cost for producing such glasses. The reduction in rare earth content reduces the cost of the production process. Investigating whether it is possible to prepare glasses with low rare earth (such as Dy and Sm) contents is valuable. In this work, the impacts of Dy2O3/ Sm2O3 substitutions on borate glass's structural, optical, and mechanical features were investigated. The optical studies reflected the structural modifications. For example, Urbach tail increased from 0.39 to 0.69 eV with further Dy2O3/ Sm2O3 substitutions. This increasing behavior refers to a less stable glass matrix. This outcome was substantiated by the diminished values of all elastic parameters in the current glasses upon additional Dy2O3/ Sm2O3 substitutions. Nonlinear optical parameters were examined across various wavelengths and compositions, revealing negligible variations within the visible and near-infrared (Vis-NIR) spans. However, a notable decrease was observed in the UV region, exhibiting a rapid decline with increasing substitutions. Furthermore, induced defects within the internal structure of the glassy network, notably non-bridging oxygens with additional Dy2O3/ Sm2O3 substitution, resulted in heightened nonlinear optical parameters. Simultaneously, all elasticity moduli decreased with further Dy2O3 additions in the current glassy system, attributed to increased disorder caused by defect production, dangling bonds, and non-bridging oxygens in the glassy matrix.In addition, the half-value layers of all glass samples were compared to those of typical and widely used shielding materials. Through this analysis, certain glass samples demonstrated superior qualities compared to conventional shielding materials. Notably, the glass sample with the highest Sm2O3 level (and correspondingly the lowest Dy2O3 value) exhibited particularly favorable attributes. Consequently, our glass samples show potential as effective shields in nuclear radiation environments.