Structural and crystallization behavior of (Ba,Sr)TiO₃ borosilicate glasses

Avadhesh Kumar Yadava, C.R. Gautama*, Arvind Gautamb & Vijay Kumar Mishrac a Department of Physics , University of Lucknow , Lucknow 226007 , Uttar Pradesh , India b North East Institute of Science and Technology , Jorhat 785006 , Assam , India c Department of Physics , Banaras Hindu University , Varanasi 221005 , Uttar Pradesh , India * E-mail: gautam_ceramic@yahoo.com Various glass samples were prepared by melt quench technique in the glass system [(Ba1− x Sr x ) TiO3]–[2SiO2–B2O3]–[K2O] doped with 1 mole% of La2O3. Infrared spectra show the number of absorption peaks with different spliting in the wave number range from 450 to 4000 cm−1. Absorption peaks occurs due to asymetric vibrational streching of borate by relaxation of the bond B–O of trigonal BO3. Raman spectra show the Raman bands due to ring-type metaborate anions, symmetric breathing vibrations BO3 triangles replaced by BO4 tetrahedra, and symmetric breathing vibrations of six-member rings. The differential thermal analysis of a glass sample corresponding to composition x = 0.0 shows crystallization temperature at 847°C and glass transition temperature at 688°C. X-ray diffraction (XRD) pattern of glass ceramic samples shows the major crystalline phase of BaTiO3 whereas pyrochlore phases of barium titanium silicate. Scanning electron micrographs confirm the results of XRD as barium titanate is major crystalline phase along with pyrochlore phase of barium titanium silicate.