Characterization and physical properties of Li2O–CaF2–P2O5 glass ceramics with Cr2O3 as a nucleating agent—Physical properties

✍ Scribed by G. Murali Krishna; B. Anila Kumari; M. Srinivasa Reddy; N. Veeraiah

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 431 KB
• Volume: 180
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2007.07.025

✦ Synopsis

In this paper, studies on various physical properties, viz., dielectric properties (dielectric constant, loss tan d, a.c. conductivity s) over a wide range of frequency and temperature, optical absorption, ESR at liquid nitrogen temperature and magnetic susceptibility at room temperature of Li 2 O-CaF 2 -P 2 O 5 : Cr 2 O 3 glass ceramics, have been reported. The optical absorption, ESR and magnetic susceptibility studies indicate that the chromium ions exist in Cr 5+ , Cr 4+ and Cr 6+ states in addition to Cr 3+ state in these samples. The dielectric constant and loss variation with the concentration of Cr 2 O 3 have been explained on the basis of space charge polarization mechanism. The dielectric relaxation effects exhibited by these samples have been analysed by a graphical method and the spreading of dielectric relaxation has been established. The a.c. conductivity in the high-temperature region seems to be connected both with electronic and ionic movements.