Raman studies and some physical properties of selected (PbO) sub(x)Nb sub(2)O sub(5)) sub(y)TeO sub(2)) sub(1-) sub(x) sub(-) sub(y)glasses

• Published in: Optical materials Vol. 32; no. 9; pp. 950 - 955
• Main Authors: Ozdanova, Jitka, Ticha, Helena, Tichy, Ladislav
• Format: Journal Article
• Language: English
• Published: 01.07.2010
• Subjects: Glass; Nonlinearity; Oxides; Physical properties; Raman scattering; Refractive index; Refractivity; Temperature dependence
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2010.01.031

Selected Nb sub(2)O sub(5)-TeO sub(2), PbO-Nb sub(2)O sub(5)-TeO sub(2) and PbO-TeO sub(2) glasses were prepared from very pure oxides. The glass-transition temperature increased from 281 to 411 degree C with an increase in Nb sub(2)O sub(5) content and, simultaneously, the coefficient of thermal expansion decreased from 21 to 11 ppm/ degree C. Raman scattering measurements indicated that TeO sub(4) trigonal bipyramids, TeO sub(3+1), TeO sub(3) trigonal unit and NbO sub(6) octahedra were the basic structural units of Nb sub(2)O sub(5)-TeO sub(2) and PbO-Nb sub(2)O sub(5)-TeO sub(2) glasses. The optical band gap was determined in the region 3.39-3.60 eV and the coefficient of the temperature dependence of the optical gap for the temperatures between 30 and 250 degree C in the region 4.1 x 10 super(-4)-6.8 x 10 super(-4) eV/K was found. Non-linear refractive index of the studied glasses was estimated from the optical gap values at around 0.85 x 10 super(-11) esu.