Gs College

Buldhana, India

Gs College

Buldhana, India
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Gawande A.B.,Sant Gadge Baba Amravati University | Ingle J.T.,J D Institute Of Engineering And Technology | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Journal of Luminescence | Year: 2014

The powder samples of SrB4O7:Pb2+ and SrB2O4:Pb2+ were prepared by solution combustion synthesis method. The synthesis is based on the exothermic reaction between the fuel (Urea) and Oxidizer (Ammonium nitrate). The synthesized materials were characterized using TG-DTA, powder XRD, SEM and the photoluminescence properties were studied using a Hitachi F-7000 spectrophotometer at room temperature. Both the samples SrB4O 7:Pb2+ and SrB2O4:Pb2+ show broad emission of Pb2+ respectively at 307 nm and 360 nm (corresponds to 3P1 to 1S0 transition). The optimum concentrations of Pb2+ in both the phosphors SrB4O7:Pb2+ and SrB2O 4:Pb2+ were found to be 3 mol% (relative to Sr) and for this concentration the critical transfer distance R0 were calculated to be 10.21 Å and 12.22 Å respectively. The Stokes shifts were calculated to be respectively 4464 cm-1 and 8454 cm-1. The emission bands of both the phosphors are in the UV region and the phosphors can be potential candidates for application in UV lamps. © 2014 Elsevier B.V.


Palaspagar R.S.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Journal of Materials Science: Materials in Electronics | Year: 2016

Energy transfer in Ce3+ and Tb3+ co-doped Li2Al2B2O7 (LABO) phosphors were synthesized by using the solution combustion method. The phase and photoluminescent properties of Ce3+ and Tb3+ co-doped LABO phosphors were investigated by using the powder X-ray diffraction and photoluminescence emission and excitation spectra. The results show that under the excitation of 357 nm wavelengths, it exhibited blue emission corresponding to the f–d transition of Ce3+ ions and green emission bands corresponding to the f–f transition of Tb3+ ions, respectively. Overlapping observed between the emission spectrum of Ce3+ ion and the excitation spectrum of Tb3+ ion due to energy transfer occurred from Ce3+ to Tb3+ in LABO host. The energy transfer efficiency from Ce3+ ion to Tb3+ ion was also calculated to be 68 %. Furthermore, thermal analysis, concentration quenching and critical distance of LABO:Ce3+,Tb3+ phosphors were also discussed. © 2016 Springer Science+Business Media New York


Gawande A.B.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Journal of Luminescence | Year: 2014

Pb2+ doped KCa4(BO3)3 materials were prepared by a novel solution combustion synthesis technique which is slight variation of combustion synthesis method. The synthesized materials were characterized by powder XRD and FT-IR. Scanning Electron Microscopy (SEM) observation indicated that the microstructure of the phosphor consisted of irregular grains which get finer and shaped in doped sample as compared to pure. The photoluminescence properties of synthesized materials were investigated using Spectrofluorometer at room temperature. The emission and excitation bands of the synthesized phosphors were observed at 335 nm and 260 nm respectively. The concentration of Pb2+ for which optimum emission is obtained was found to be 0.005 mol. The critical transfer distance (R0) for optimum concentration was determined to be 16.88 Å. The Stokes shift of KCa4(BO3)3:Pb2+ was measured to be 8756 cm-1. The phosphor could find application in medical and lamp industry. © 2014 Elsevier B.V.


Palaspagar R.S.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Journal of Materials Science: Materials in Electronics | Year: 2016

A series of red-emitting alumino-borate phosphors (NCABO) with chemical composition of NaCa0.5Al2B2O7:xEu3+ (0.5–4 mol%) has been synthesized by using slow evaporation technique. X-ray diffraction (XRD), FE-SEM and photoluminescence measurements were performed to testify the crystal structure, surface morphology and luminescent properties. The present phosphor exhibits a strong broad absorption in the near ultraviolet (n-UV) (~395 nm), which is matched well with the emission wavelength of n-UV LED chip. The most intense red emission was found at ~616 nm when doped Eu3+ content was 3 mol%. All the samples show the characteristic red emission of Eu3+ ions (5D0 → 7FJ, J = 0, 1, 2, and 3), suggesting that the phosphor is competitive as a promising red-emitting phosphor for n-UV light-emitting diodes (LEDs). The optimal Eu3+ concentration was determined, and the mechanism of the concentration quenching was predominated by dipole–dipole interaction. © 2016 Springer Science+Business Media New York


Gawande A.B.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
International Journal of Optics | Year: 2014

The photoluminescence properties of Pb2+ and Bi3+ doped Ca3(BO3)2 prepared by solution combustion synthesis technique are discussed. The structure of the prepared phosphor is characterized and conformed by XRD and FTIR. SEM images of the prepared materials show irregular grains with agglomerate phenomena. Prepared phosphors achieved the band emissions, respectively, at 365 nm and 335 nm corresponding to the transition P 1 → S 0 1 3. Optimum concentration, critical transfer distance, and Stokes shift of the synthesized materials were measured. These phosphors may provide an efficient kind of luminescent materials for various applications in medical and industry. © 2014 A. B. Gawande et al.


Gawande A.B.,Sant Gadge Baba Amravati University | Sonekar R.P.,Sant Gadge Baba Amravati University | Omanwar S.K.,Gs College
Materials Research Bulletin | Year: 2014

The photoluminescence properties of (Sr1-xPrx)2Mg(BO3)2; (Sr1-2xPrxMx)2Mg(BO3)2,(M = Li, Na, K); (Sr1-xGdx)2Mg(BO3)2; (Sr1-2xGdxMx)2Mg(BO3)2, (M = Li, Na, K) and (Sr1-4xPrxGdxNa2x)2Mg(BO3)2inorganic phosphors prepared by solution combustion synthesis technique are discussed. The structure of the prepared phosphor characterized using Thermogravimetric-differential thermal analysis, X-ray diffraction and fourier transform-infrared. Scanning electron microscopy images of the prepared materials show irregular grains with agglomerate phenomena. Photoluminescence properties were studied at room temperature. Optimum concentration and critical transfer distance of the synthesized phosphors were determined. © 2014 Elsevier Ltd. All rights reserved.


Palaspagar R.S.,Sant Gadge Baba Amravati University | Gawande A.B.,Gs College | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Materials Research Bulletin | Year: 2015

Novel LiAl7B4O17 (LABO) phosphor activated with trivalent rare earth ions (RE = Tb, Sm) was synthesized by using solution combustion synthesis. The powder X-ray diffraction (XRD), field emission-scanning electron microscope (FE-SEM), photoluminescence (PL), critical transfer distance (Rc) and quenching mechanism studies were employed to characterize the samples. Under ultraviolet irradiation of the LiAl7B4O17: Tb3+, Sm3+ phosphors exhibit the typical green (5D4 → 7Fj = 6, 5, 4 and 3) emission band of the Tb3+ ions, as well as an orange-red and red (4G5/2 → 6HJ=5/2, 7/2, 9/2) emission bands of the Sm3+ ions. These results suggest that Tb3+ and Sm3+ activated LABO phosphor could be promising in vision of the necessity for solid state lighting applications. © 2015 Elsevier Ltd. All rights reserved.


Gawande A.B.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Optical Materials | Year: 2014

Photoluminescence properties of Ce3+ doped strontium haloborates synthesized by solution combustion technique were studied. Sr2B 5O9Cl:Ce3+ produce emission band peaking at 345 nm under 307 nm excitation radiation. Enhancement of luminescence intensity was observed when M+ (Li+, Na+, K+) ions were used as co-dopant in Sr2B5O9Cl: Ce3+. Charge compensation by Na+ ion in Sr 2B5O9Cl:Ce3+ show strongest luminescence intensity at 345 nm under 307 nm excitation radiation. © 2014 Elsevier B.V. All rights reserved.


Gawande A.B.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Combustion Science and Technology | Year: 2014

YBO3: Gd3+, YBO3:Gd3+, Bi 3+, and YBO3:Gd3+, Pr3+ phosphors were synthesized by the combustion synthesis method. The phase analysis of all synthesized materials was determined using powder X-ray diffraction (XRD). Photoluminescence properties and concentration quenching of these phosphors were systematically investigated. All the samples show the characteristic narrow band UVB emission of Gd3+ ions (6PJ → 8S7/2). The maximum intensity of luminescence in synthesized materials was investigated. The energy transfer mechanism was studied using Bi3+ and Pr3+ as sensitizers, and it is observed that as compared to Bi3+, Pr3+ effectively transfers its energy to Gd3+. The Stokes shifts of YBO 3:Gd3+, YBO3:Gd3+-Bi3+, and YBO3:Gd3+-Pr3+ phosphors were calculated to be 4181 cm-1, 6410 cm-1, and 7949 cm-1, respectively. Copyright ©; 2014 Taylor & Francis Group, LLC.


Gawande A.B.,Sant Gadge Baba Amravati University | Sonekar R.P.,Gs College | Omanwar S.K.,Sant Gadge Baba Amravati University
Combustion Science and Technology | Year: 2014

Inorganic borate host phosphor BaB2O4 doped with varying concentrations of Pb2+ has been prepared by a solution combustion synthesis technique. The synthesis is based on the exothermic reaction between the fuel (urea) and oxidizer (ammonium nitrate). The photoluminescence properties of prepared materials were studied at room temperature. Under the excitation of 240 nm, the phosphor BaB2O4:Pb2+ shows broad emission at 370 nm (corresponds to 3P1 to 1S0 transition). The optimum concentration of Pb2+ in BaB2O4:Pb2+ was found to be 0.02 mol (relative to Ba). The critical transfer distances, R0 were calculated. Stokes shifts were calculated (using corresponding excitation and emission band peaks) to be 14,640 cm-1. The emission bands of synthesized phosphors are in the ultraviolet (UV) region and could be potential candidates for application in UV lamps. © Taylor and Francis Group, LLC.

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