Multifunctional characterization of biocompatible P2O5-based glasses: Radiation shielding, electrical conductivity, and dielectric relaxation

Abstract

This study investigates the structural, dielectric, and electrical properties of phosphate-based glasses modified by replacing P₂O₅ with Fe₂O₃. Using Fourier transform infrared (FTIR) spectroscopy and conductivity measurements, the findings confirm the amorphous nature of the glasses prepared via the fast-quench method. The substitution of Fe₂O₃ impacts the phosphate glass lattice by reducing oxygen content, modifying vibration modes, and increasing glass humidity, which enhances the dielectric constant and radiation shielding efficiency. Temperature-dependent conductivity measurements reveal distinct thermally activated behavior, correlated barrier hopping (CBH) at temperature range (300–500 K). The conductivity changes are attributed to Fe₂O₃'s multivalent semiconductor role, which modifies the glass network and facilitates charge carrier mobility. Furthermore, the study highlights the dielectric modulus as a more reliable indicator of relaxation behavior compared to the dielectric constant, as it minimizes distortion from electrode polarization. The substitution of Fe₂O₃ caused both the activation energy ΔE_d and the characteristic relaxation time τ_o to change from 0.723 eV to 0.81 eV and from 53 s to 3.53 s, respectively. This gradual increase in dielectric activation energy (ΔE_d) due to increased structural rigidity and reduced free space in the glass matrix with higher Fe₂O₃ content. These findings underscore the potential of Fe₂O₃-modified phosphate glasses for applications in electronics, optoelectronics, and energy storage devices.