title: Synthesis, characterization and photoluminescence properties of CaSiO3:Eu3+ red phosphor.
abstract: CaSiO3:Eu3+ (1-5 mol%) red emitting phosphors have been synthesized by a low-temperature solution combustion method. The phosphors have been well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and optical spectroscopy. PXRD patterns reveal monoclinic CaSiO3 phase can be obtained at 900°C. The SEM micrographs show the crystallites with irregular shape, mostly angular. Upon 254 nm excitation, the phosphor show characteristic fluorescence 5D0→7FJ (J=0, 1, 2, 3, 4) of the Eu3+ ions. The electronic transition located at 614 nm corresponding to 5D0→7F2 of Eu3+ ions, which is stronger than the magnetic dipole transition located at 593 nm corresponding to 5D0→7F1 of Eu3+ ions. Different pathways involved in emission process have been studied. Concentration quenching has been observed for Eu3+ concentration>4 mol%. UV-visible absorption shows an intense band at 240 nm in undoped and 270 nm in Eu3+ doped CaSiO3 which is attributed to oxygen to silicon (O-Si) ligand-to-metal charge-transfer (LMCT) band in the SiO3(2-) group. The optical energy band gap is widened with increase of Eu3+ ion dopant.
authors.affiliation: Advanced Materials Research Centre, Department of PG studies & Research in Physics, University Science College, Tumkur University, Tumkur 572103, India. bhushanvl@rediffmail.com
authors.forename: H
authors.initials: H
authors.lastname: Nagabhushana
authors.forename: B M
authors.initials: BM
authors.lastname: Nagabhushana
authors.forename: M
authors.initials: M
authors.lastname: Madesh Kumar
authors.lastname: Chikkahanumantharayappa
authors.forename: K V R
authors.initials: KV
authors.lastname: Murthy
authors.forename: C
authors.initials: C
authors.lastname: Shivakumara
authors.forename: R P S
authors.initials: RP
authors.lastname: Chakradhar
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D017640:Silicates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D017610:Calcium Compounds; D017640:Silicates; D005063:Europium; C031293:calcium silicate