Structural and dielectric studies of MBi2B2O7(M = Sr&Ba) glass- Bi24B2O39 microcrystal composites

20MO.55Bi ₂O ₃.25B ₂O ₃ (M = Sr, Ba) glasses have been prepared by conventional melt quenching method and the Bi ₂₄B ₂O ₃₉ (boron sillenite) crystalline phase by solid state reaction technique. The effect of variation in wt% of Bi ₂₄B ₂O ₃₉ crystalline phase on 20SrO.55Bi ₂O ₃.25B ₂O ₃ (SBB) and 20BaO.55Bi ₂O ₃.25B ₂O ₃ (BBB) glasses has been investigated. The sintered density of the glass samples were characterized by Archimedes` method. The X-ray Diffraction method, Fourier Transform-Infrared (FT-IR) spectra and FT- Raman spectra are used for structural investigations, whereas Scanning Electron Microscope (SEM) analysis is used for the microstructural study. The effect of the Bi ₂₄B ₂O ₃₉ crystalline phase as filler in the glass network is confirmed from the FT-IR and FT-Raman spectra. The dielectric properties of the selected samples, analyzed using an Impedance analyzer, show that the dielectric constant slightly increases with increase in the wt% of Bi24B2O39 crystalline phase on glasses and the BBB glasses show higher dielectric values than the SBB glasses. The glass ceramic composites show low sintering temperature (<650 °C), dielectric constant in the range 10–16 and dielectric loss of ~0.0069, suggesting that they can be used as promising candidates for Ultra Low Temperature Cofired Ceramic Applications(ULTCC).