Synthesis, characterization, photoluminescence and EPR investigations of Mn doped MgAl{sub 2}O{sub 4} phosphors

Journal Article · Sun Jul 15 00:00:00 EDT 2007 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2007.04.030· OSTI ID:21015874

Singh, Vijay ^[1]; Chakradhar, R P.S. ^[2]; Rao, J L ^[3]; Kim, Dong-Kuk ^[1]

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1. Department of Chemistry, Kyungpook National University, Daegu 702701 (Korea, Republic of)
2. Glass Technology Lab, Central Glass and Ceramic Research Institute, Kolkata 700032 (India)
3. Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

MgAl{sub 2}O{sub 4}:Mn phosphors have been prepared at 500 deg. C by combustion route. Powder X-ray diffraction (XRD) indicated the presence of mono-MgAl{sub 2}O{sub 4} phase. Scanning electron microscopy showed that the powder particle crystallites are mostly angular. Fourier transform infrared spectroscopy confirmed the presence of AlO{sub 6} group which makes up the MgAl{sub 2}O{sub 4} spinel. Photoluminescence studies showed green/red emission indicating that two independent luminescence channels in this phosphor. The green emission at 518 nm is due to {sup 4} T {sub 1} {sup {yields}}{sup 6} A {sub 1} transition of Mn{sup 2+} ions. The emission at 650 nm is due to the charge-transfer deexcitation associated with the Mn ion. EPR spectrum exhibits allowed and forbidden hyperfine structure at g=2.003. The g{approx}2.00 is due to Mn{sup 2+} ion in an environment close to tetrahedral symmetry. It is observed that N and {chi} increase with decrease of temperature obeying the Boltzmann law. The variation of zero-field splitting parameter (D) with temperature is evaluated and discussed. - Graphical abstract: MgAl{sub 2}O{sub 4}:Mn phosphors have been prepared at 500 deg. C by combustion route and are well characterized by PXRD, SEM and FTIR. Photoluminescence studies showed green/red emission indicating two independent luminescence channels in this phosphor. EPR spectrum exhibits allowed and forbidden hyperfine structure at g=2.003. From EPR spectra the spin-Hamiltonian parameters have been evaluated and discussed.

• OSTI ID: 21015874
• Journal Information: Journal of Solid State Chemistry, Vol. 180, Issue 7; Other Information: DOI: 10.1016/j.jssc.2007.04.030; PII: S0022-4596(07)00175-2; 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
ALUMINIUM OXIDES
COMBUSTION
DE-EXCITATION
DOPED MATERIALS
ELECTRON SPIN RESONANCE
FOURIER TRANSFORM SPECTROMETERS
FOURIER TRANSFORMATION
HAMILTONIANS
HYPERFINE STRUCTURE
INFRARED SPECTRA
MAGNESIUM COMPOUNDS
MANGANESE COMPOUNDS
MANGANESE IONS
PHOSPHORS
PHOTOLUMINESCENCE
POWDERS
SCANNING ELECTRON MICROSCOPY
SPIN
SPINELS
X-RAY DIFFRACTION