Physical, FTIR, ultrasonic, and dielectric characteristics of calcium lead-borate glasses mixed by Nd2O3/Er2O3 rare earths: experimental study

Physical, FTIR, ultrasonic, and dielectric characteristics of calcium lead-borate glasses: 50B2O3–30CaO–20PbO–xEr2O3–yNd2O3:` (x,y) = (0,0; BCP), (0,1;1Nd), (1,0;1Er), and (1,1;1Nd–1Er) mol% have been examined. Nd3+ ions increased density up to 3857 kg/m3, meanwhile, molar volume barely changed. Er2O3 mol% decreased density down to 3641 kg/m3, while molar volume increased up to 2.75 × 10–5 m3. As well, Nd2O3 mol% + Er2O3 mol% decreased density down to 3556 kg/m3, while molar volume increased up to 2.91 × 10–5 m3. Er3+ and Nd3+ ions have different effects on the formation rate of BØ−4 and BØ2O− structural units. PbO in the glassy systems can be incorporated into the glass as network-forming Pb–O groups (PbO4 and/or PbO3). Introducing of Nd3+ ions induces changes in the local field on the lead ions giving rise to the formation of [PbO4] units. The addition of Er 3+ and/or Nd3+ to glass systems revealed that there was observed withdrawal of the area of PbO4- absorption IR band and increasing both of longitudinal and shear velocity. The elastic moduli of the investigated glasses have a fingerprint of density behavior versus rare-earth content. Dielectric constant and ac conductivity were obviously enhanced by the insertion of Nd3+/Er3+ ions separately or together into borate glass matrix referring to the creation of non-bridging oxygen.