title: Synthesis, EPR and luminescent properties of YAlO3:Fe3+ (0.1-0.9mol%) nanopowders.
abstract: A simple and inexpensive combustion method was used to prepare Fe(3+) doped YAlO3 perovskite within few minutes at low temperature (400±10°C). This might be useful in lowering the cost of the material. The final products were well characterized by various spectroscopic techniques such as PXRD, SEM, TEM, FTIR and UV-Visible. The average crystallite size was estimated from the broadening of the PXRD peaks and found to be in the range 45-90nm, the results were in good agreement with the W-H plots and TEM. The crystallites show dumbbell shape, agglomerated particles with different size. The TL glow curves of 1-5kGy γ-irradiated YAlO3:Fe(3+) (0.1mol%) nanopowder warmed at a heating rate of 3°Cs(-1) records a single glow peak at ∼260°C. The kinetic parameters namely activation energy (E), order of kinetics (b) and frequency factor (s) were determined at different gamma doses using the Chens glow peak shape method and the results were discussed in detail. The photoluminescence spectra for Fe(3+) (0.1-0.9mol%) doped YAlO3 records the lower energy band at 720nm ((4)T1 (4G)→(6)A1 (6S)) and the intermediate band located at 620nm ((4)T2 ((4)G)→(6)A1 (6S)) with the excitation of 378nm. The higher energy band located at 514nm was associated to (4)E+(4)A1 ((4)G)→(6)A1 (6S) transition. The resonance signals at g values 7.6, 4.97, 4.10, 2.94, 2.33 and 1.98 were observed in EPR spectra of Fe(3+) (0.1-0.9mol%) doped YAlO3 recorded at room temperature. The g values indicate that the iron ions were in trivalent state and distorted octahedral site symmetry was observed.
authors.affiliation: Department of Physics, Acharya Institute of Technology, Bangalore 560090, India.
authors.forename: H B
authors.initials: HB
authors.lastname: Premkumar
authors.affiliation: Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572103, India. Electronic address: bhushanvlc@gmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Nagabhushana
authors.affiliation: Vice Chancellor, Chhattisgarh Swamy Vivekananda Technical University, North Park Avenue, Sector - 8, Bhilai, Chhattisgarh 490 009, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Sharma
authors.affiliation: Department of Physics, B.M.S. Institute of Technology, Bangalore 560064, India.
authors.forename: B
authors.initials: B
authors.lastname: Daruka Prasad
authors.affiliation: Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560054, India.
authors.forename: B M
authors.initials: BM
authors.lastname: Nagabhushana
authors.affiliation: Department of Physics, S.V. University, Tirupathi 517502, India.
authors.forename: J L
authors.initials: JL
authors.lastname: Rao
authors.affiliation: CSIR-National Aerospace Laboratories (CSIR), Bangalore 560017, India.
authors.forename: R P S
authors.initials: RP
authors.lastname: Chakradhar
mesh_terms: D017607:Aluminum Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D017610:Calcium Compounds / Q000138:chemical synthesis / Q000737:chemistry; D002412:Cations / Q000138:chemical synthesis / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D007501:Iron / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D008163:Luminescent Measurements; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010087:Oxides / Q000138:chemical synthesis / Q000737:chemistry; D011208:Powders; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D002412:Cations; D049408:Luminescent Agents; D010087:Oxides; D011208:Powders; C059910:perovskite; D015019:Yttrium; D014025:Titanium; D007501:Iron
keywords: Combustion synthesis; Optical absorption; Phosphor; Photoluminescence