Characterization and physical properties of Li{sub 2}O-CaF{sub 2}-P{sub 2}O{sub 5} glass ceramics with Cr{sub 2}O{sub 3} as a nucleating agent-Physical properties

Journal Article · Mon Oct 15 00:00:00 EDT 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.07.025· OSTI ID:21049506

Murali Krishna, G; Anila Kumari, B; Srinivasa Reddy, M ^[1]

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1. Department of Physics, Acharya Nagarjuna University - Nuzvid Campus, Nuzvid 521 201 (India)

In this paper, studies on various physical properties, viz., dielectric properties (dielectric constant, loss tan {delta}, a.c. conductivity {sigma}) over a wide range of frequency and temperature, optical absorption, ESR at liquid nitrogen temperature and magnetic susceptibility at room temperature of Li{sub 2}O-CaF{sub 2}-P{sub 2}O{sub 5}: Cr{sub 2}O{sub 3} glass ceramics, have been reported. The optical absorption, ESR and magnetic susceptibility studies indicate that the chromium ions exist in Cr{sup 5+}, Cr{sup 4+} and Cr{sup 6+} states in addition to Cr{sup 3+} state in these samples. The dielectric constant and loss variation with the concentration of Cr{sub 2}O{sub 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. - Graphical abstract: The optical absorption spectroscopic studies on Li{sub 2}O-CaF{sub 2}-P{sub 2}O{sub 5}: Cr{sub 2}O{sub 3} glass ceramics indicate that a part of Cr{sup 3+} ions oxidized into Cr{sup 6+} ions during the crystallization. These ions enter the glass network with CrO{sub 4}{sup 2-} structural units, alternate with PO{sub 4} units and increase the rigidity of the glass-ceramic sample.

• OSTI ID: 21049506
• Journal Information: Journal of Solid State Chemistry, Vol. 180, Issue 10; Other Information: DOI: 10.1016/j.jssc.2007.07.025; PII: S0022-4596(07)00278-2; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION
CALCIUM FLUORIDES
CERAMICS
CHROMIUM IONS
CHROMIUM OXIDES
CRYSTALLIZATION
DIELECTRIC MATERIALS
ELECTRON SPIN RESONANCE
GLASS
LITHIUM OXIDES
MAGNETIC SUSCEPTIBILITY
NITROGEN
PERMITTIVITY
PHOSPHORUS OXIDES
POLARIZATION
TEMPERATURE RANGE 0273-0400 K