Synthesis, characterization and spectroscopic investigation of Cr3+ doped wollastonite nanophosphor

Kumar, Madesh M and Nagabhushana, H and Nagabhushana, BM and Suriyamurthy, N and Sharma, SC and Shivakumara, C and Krishna, Hari R (2014) Synthesis, characterization and spectroscopic investigation of Cr3+ doped wollastonite nanophosphor. In: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, 128 . pp. 403-407.

PDF spe_act_par_mel_bio_spe_128_403_2014.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

This work explores the preparation of nanocrystalline Cr3+ (1-5 mol%) doped CaSiO3 phosphors by solution combustion process and study of its photoluminescence (PL) behavior. The nanopowders are well characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra-red (FTIR) spectroscopy. PXRD results confirm monoclinic phase upon calcination at 950 degrees C for 3 h. SEM micrographs indicates that the powder is highly porous and agglomerated. The TEM images show the powder to consist of spherical shaped particles of size similar to 30-60 nm. Upon 323 nm excitation, the emission profile of CaSiO3:Cr3+ exhibits a narrow red emission peak at 641 nm due to E-2 -> (4)A(2) transition and broad band at 722 nm due to T-4(2g) -> (4)A(2g). It is observed that PL intensity increases with increase in Cr3+ concentration and highest PL intensity is observed for 3 mol% doped sample. The PL intensity decreases with further increase in Cr3+ doping. This decrease in PL intensity beyond 3 mol% is ascribed to concentration quenching. Racah parameters are calculated to describe the effects of electron-electron repulsion within the crystal lattice. The parameters show 21% reduction in the Racah parameter of free ion and the complex, indicating the moderate nephelauxetic effect in the lattice. (C) 2014 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copyright for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Keywords:	Silicates; Nanophosphor; Solution combustion; Photoluminescence
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	18 Jun 2014 06:00
Last Modified:	18 Jun 2014 06:00
URI:	http://eprints.iisc.ac.in/id/eprint/49239

Actions (login required)

View Item