Abstract
Physical, FTIR, ultrasonic, and dielectric characteristics of calcium lead-borate glasses: 50B(2)O(3)-30CaO-20PbO-xEr(2)O(3)-yNd(2)O(3):` (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/m(3), meanwhile, molar volume barely changed. Er2O3 mol% decreased density down to 3641 kg/m(3), while molar volume increased up to 2.75 x 10(-5) m(3). As well, Nd2O3 mol% + Er2O3 mol% decreased density down to 3556 kg/m(3), while molar volume increased up to 2.91 x 10(-5) m(3). Er3+ and Nd3+ ions have different effects on the formation rate of Bo(4)(-) and Bo(2)O(-) 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.