Abstract
Lead-borate glasses reinforced by Er3+ and Nd3+ ions with the form 50B2O3–30CaO–20PbO-0.5Er2O3-x (Nd2O3), where x = 0–1.50 mol% labelled as S1–S7 were fabricated utilizing the traditional melt quenching technique. Physical, structure, ultrasonic mechanical, and dielectric properties of the proposed glasses were investigated. The density of the glass system showed a decrement from 3757 to 3646 kg/m3. The molar volume increased from 2.566 × 10−5 m3 for glass sample S1 to 2.831 × 10−5 m3 for glass sample S7. Introduction of Nd3+ and Er3+ ions induced amplified changes in the local field on the lead ions giving rise to occur the forming of [PbO4] units. The average boron–boron separation (dB–B) varied from 3.49 × 10−10 to 3.61 × 10−10 Å for samples S1 and S7, respectively. The Nd3+ ions concentration takes values from 0 for S1 glass sample to 10.7 × 1025 ions m−3 for S7 glass sample. The N4 decreased with increasing rare earth ions content in glass composition. In contrast, the N3 which refers to the absorption band area related to the [BO3] group, increased. VL and VS increased from 5289 to 5529 ms−1 and from 2906 to 3093 ms−1, respectively with addition of Er3+ and increasing of Nd3+ ions from 0 (S1 sample) to 1.5 (S7 sample) mol%. The enhancement in dielectric constant was clearly observed. It increased from 25.4 to 55.3 with the change in composition from S1 to S7 at 50 kHz frequency. The ac conductivity was enhanced with increasing applied frequency especially at the high-frequency range.