Materials Characterization of Potassium Sodium Niobate based Tellurite Glass-Ceramics

Abstract

In this research, materials characterization of transparent glass-ceramics containing ferroelectric potassium sodium niobate (K_0.5Na_0.5)NbO₃ (KNN) crystals in a tellurite glass system were studied. The samples were prepared via an incorporation method. Glass-ceramics containing KNN crystals were successfully fabricated by mixing KNN calcined powder with TeO₂ of about 70 and 80 mol% and melting at 800°C for 15 min in a platinum crucible. The prepared glasses were then subjected to heat treatment at 350–550°C. The optical properties of the samples were characterized by UV-Vis-NIR and ellipsometer. It was found that heat treatment temperature had significantly affected the optical properties. XRD patterns of the glass-ceramics revealed an amorphous-like structure with different degrees of crystallinity. SEM results confirmed the XRD data, where the degree of crystallinity increased with increasing heat treatment temperature.

Keywords:

• Potassium sodium niobate
• Glass-ceramics
• Tellurium dioxide

Acknowledgments

The authors would like to express their sincere gratitude to the Thailand Research Fund, National Metal and Materials Technology Center, and Faculty of Science, Chiang Mai University for financial support. We wish to thank the Graduate School Chiang Mai University and The National Research University Project under Thailand's Office of the Higher Education Commission for financial support. P. Yongsiri would like to thank the Thailand Graduate Institute of Science and Technology for her scholarship.