In this study, for the first time, diamagnetic 5d⁰ Ta⁵⁺ ions and Ta₂O₅ nanocrystals were utilized to enhance the structural, mechanical, magnetic, and radiation shielding of heavy metal oxide glasses. Transparent Ta₂O₅ nanocrystal-doped heavy metal oxide glasses were obtained, and the embedded Ta₂O₅ nanocrystals had sizes ranging from 20 to 30 nm. The structural analysis of the Ta₂O₅ nanocrystal displays the transformation from hexagonal to orthorhombic Ta₂O₅. Structures of doped glasses were studied through X-ray diffraction and infrared and Raman spectra, which reveal that Ta₂O₅ exists in highly doped glass as TaO₆ octahedral units, acting as a network modifier. Ta⁵⁺ ions strengthened the network connectivity of 1–5% Ta₂O₅-doped glasses, but Ta⁵⁺ acted as a network modifier in a 10% doped sample and changed the frame coordination units of the glass. All Ta₂O₅-doped glasses exhibited improved Vicker’s hardness, magnetization (9.53 × 10⁻⁶ emu/mol), and radiation shielding behaviors (RPE% = 96–98.8%, MAC = 32.012 cm²/g, MFP = 5.02 cm, HVL = 0.0035–3.322 cm, and Z_eff = 30.5) due to the increase in density and polarizability of the Ta₂O₅ nanocrystals.

Diamagnetic ${\mathrm{TeO}}_2\text{-}\mathrm{ZnO}\text{-}{\mathrm{Na}}_2\mathrm{O}$ glasses and fibers were fabricated and characterized for magneto-optical current-sensor applications. Two prototypes based on the obtained glass and fibers were constructed. An analysis of the distribution of the magnetic field flux inside the conductor was performed. Hardware and developed software were constructed for the acquisition of weak output signals induced by a low current. The good sensitivities of the fiber magneto-optical current transducer and the bulk magneto-optical current transducer are due to the high Verdet constant and homemade signal-acquisition hardware.