Singh, Vijay and Chakradhar, R P S and Rao, J L and Kwak, Ho-Young (2011) EPR and photoluminescence properties of Mn(2+)-activated zinc gallate phosphor prepared by urea combustion route and post heat treatment. Journal of Luminescence, 131 (8). pp. 1789-1794. ISSN 0022-2313

PDF - Published Version Restricted to Registered users only Download (629Kb) | Request a copy

Abstract

Mn(2+) activated ZnGa(2)O(4) powder phosphors have been prepared by urea combustion route. Powder X-ray diffraction and scanning electron microscopy (SEM) techniques have been used to characterize the as-prepared and post-treated (900 degrees C, 3 h) phosphors. The morphology shows small particles, voids and pores, with non-uniform shapes and sizes. The EPR spectrum exhibits an intense resonance signal at g approximate to 1.985 with a sextet hyperfine structure (hfs) besides a weak broad signal at g approximate to 4.05 and a hump near g approximate to 2.27. The g approximate to 1.985 resonance is due to Mn(2+) ions in an environment close to tetrahedral symmetry. The resonances at g approximate to 4.05 and 2.27 are attributed to the rhombic surroundings of the Mn(2+) ions. The spin concentration (N) and the paramagnetic susceptibility (%) are evaluated and discussed. It is observed that the intensity of the resonance signal at g approximate to 1.985 increases with decrease in temperature obeying the Boltzmann law. Upon post treatment the intensity of the green emission (lambda(em)=528 nm,(4)T(1)->(6)A(1) transition of Mn(2+) ions) has been increased to 3.35 times and a red shift has been observed. (C) 2011 Elsevier B.V. All rights reserved.

Item Type:	Article
Uncontrolled Keywords:	Combustion; Luminescence; EPR; Mn(2+) ions; Phosphors; Zinc gallate
Subjects:	Physical Properties
Divisions:	Glass
Depositing User:	Bidhan Chaudhuri
Date Deposited:	20 Jan 2012 04:46
Last Modified:	25 Feb 2013 08:51
URI:	http://cgcri.csircentral.net/id/eprint/414

Actions (login required)

View Item