Physical and structural properties of some bismuth borate glasses

摘要: Abstract Glasses in the system ( x /2)Bi 2 O 3 –( /2)Nb 5 –(1 −  )Na B 4 7 , 0 ≤   ≤ 0.3, have been prepared by melt quenching technique. Elastic properties and Debye temperature θ D ) investigated using sound velocity measurements at 4 MHz. The ultrasonic parameters along with IR spectroscopic studies employed to study role of Bi Nb on structure Na glass. density, molar volume, velocities, glass transition temperatures these samples found be compositional dependent. results indicate that act as a network modifier range  ≤ 0.15, while beyond  = 0.15, acts former which affects diborate units mainly consist strong borate network. These are interpreted terms transformation NbO 6 into increase number non-bridging oxygen atoms, substitution longer bond lengths Bi–O, Nb–O place shorter B–O bond. observed dependence elastic moduli is effect Boron-coordination relatively large electron–phonon anharmonic interactions.