Articles
  • Thermal properties and crystallization kinetics of tellurium oxide based glasses 
  • E.D. Jeonga, J.S. Baea, T.E. Honga, K.T. Leeb, B.K. Ryub, T. Komatsuc and H.G. Kima,*
  • a Busan Center, Korea Basic Science Institute, Busan 609-735, Korea b School of Materials Science & Technology, Pusan National University, Busan 609-735, Korea c Department of Chemistry, Nagaoka University of Technology, Nagaoka 940-21, Japan
Abstract
The thermal stabilities and formation kinetics of K[Nb1/3Te2/3](2)O-4.8 phase in K2O-Nb2O5-TeO2 glasses were investigated. The activation energies for crystallization and grain growth of the K[Nb1/3TC2/3](2)O-4.8 phase from original glasses were determined from the results of XRD and DTA data. Transparent 15K(2)O-15Nb(2)O(5)-70TeO(2) glass-ceramics have a cubic structure basically, but the cubic structure is very slightly distorted. The activation energy for grain growth of the K[Nb1/3Te2/3](2)O-4.8 phase in 15K(2)O-15Nb(2)O(5)-70Te(2) glass was 33.5 kJ/mol. The energy required for the phase transformation from 15K(2)O-15Nb(2)O(5)-70TeO(2) glass to K[Nb1/3Te2/3](2)O-4.8 was 253.6 kJ/mol. The study on the formation kinetics of transparent glass-ceramics with SHG should have a large impact for the development of nonlinear optical materials.

Keywords: activation energy; thermal stability; phase transformation; nano-crystal

This Article

  • 2007; 8(6): 417-420

    Published on Dec 31, 2007