Ultrasonic Investigation on Nanocrystalline Barium Borate (BBO) Glass Ceramics

Abstract

Barium Borate (BBO) glasses containing different compositions of BaO and B₂O₃ with BaF₂, Cr₂O₃ and TiO₂ have been prepared by normal melting and annealing technique. The prepared bulk BBO glasses have been subjected to heat‐treatment. The heat‐treated BBO glasses produce nanophase BBO crystals in its structure. The existence of nanophase structure of the BBO crystals have been studied through XRD and the results reveal that the size of the particles is in the order of less than 100 nm. The SEM studies also support the observed XRD study and it explores the crystalline BBO crystal in the nano range. Further, the ultrasonic velocity, attenuation and their related parameters have been measured before and after heat‐treatment. The observed higher magnitude of variation in the ultrasonic parameters in nanophase glasses when compared with bulk glasses reveals a reduction in the particle size. The present investigation reveals that ultrasonics is one of the best tools to characterise the nanophase materials.

Keywords:

• nanophase BBO crystals
• ultrasonic velocity
• attenuation
• elastic constants

Acknowledgments

The authors are grateful to Prof. S. Balakrishnan, Principal and Thiru. A. Vairaprakasam, Correspondent, Mepco Schlenk Engineering College, for their constant encouragement to do this collaborative work.