Kzs Science College

Nāgpur, India

Kzs Science College

Nāgpur, India
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Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Atram R.G.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2011

A new phosphor in the ClF system doped with Dy, Ce and Eu has been reported. Characterization of this phosphor using XRD, PL and TL techniques is described. Polycrystalline Na6(SO4)2FCl:Dy; Na6(SO4)2FCl:Ce and Na6(SO 4)2FCl:Eu phosphors prepared by a solid state diffusion method have been studied for their X-ray diffraction, photoluminescence (PL) and thermoluminescence (TL)characteristics. The PL excitation and emission spectra of phosphors were obtained. Dy3 emission in the host at 475 and 570 nm is observed due to 4F9/2→6H 15/2 and 4F9/2→6H 13/2 transition, respectively, whereas the PL emission spectra of Na6(SO4)2FCl:Ce phosphor shows the Ce 3 emission at 322 nm due to 5d→4f transition of Ce3 ion. In Na6(SO4)2FCl:Eu lattice, Eu2 as well as Eu3 emissions are observed. The emission of europium ion in this compound exhibits the blue as well as red emission. The TL glow curves of the same compounds have the simple structure with a prominent peak at 150, 175 and 200 °C. TL response, fading, reusability and trapping parameters of the phosphors are also studied. The TL glow curves of γ-irradiated Na 6(SO4)2FCl sample show one glow peak indicating that only one set of traps is being activated within the particular temperature range each with its own value of activation energy (E) and frequency factor (s). The trapping parameters associated with the prominent glow peak are calculated using Chen's half width method. The release of hole/electron from defect centers at the characteristic trap site initiates the luminescence process in these materials. The intensity of the TL glow peaks increases with increase of the added γ-ray dose to the samples. © 2011 Elsevier B.V. All rights reserved.


Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Atram R.G.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2011

Polycrystalline KCaSO4Cl:Eu, Dy, KCaSO4Cl:Ce, Dy and KCaSO4Cl:Ce, Mn phosphors prepared by a solid state diffusion method have been studied for its photoluminescence (PL) characteristics. The presence of two overlapping bands at around 400 and 450 nm in the PL emission spectra of the phosphor suggests the presence of Eu2 in the host compound occupying two different lattice sites. The effects of co-doping on the photoluminescence (PL) characteristics of KCaSO4Cl:Eu or Ce phosphors have been studied. The decrease in peak intensity of the phosphor on co-doping it with Dy gives an insight into the emission mechanism of the phosphors, which involves energy transfer from Eu2→Dy3, Ce 3→Dy3 and Ce3→Mn2. © 2011 Elsevier B.V.


Poddar A.,Sindhu College | Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2013

Photoluminescence (PL) from Cu+, Dy3+and Eu 3+ doped KMgSO4F halosulfate fluoride phosphors have been investigated and synthesized by the wet chemical method. Strong emission of KMgSO4F: Cu+ phosphor is assigned to electronic transition 3d94s1→3d10. Emission bands peaking at 442 nm and 462 nm in the green region of the spectrum. Dy3+ emission is observed at 484 and 576 nm in KMgSO4F host due to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. The emission has a yellow-orange color in KMgSO4F host lattice The presence of trivalent Eu in KMgSO4F suggest the presence of Eu3+ in the host compound occupying two different lattice sites which is peaking at 593 and 616 nm showing 5D0→ 7F1 and 5D0→7F 2 transitions respectively. The trivalent europium ion is very useful for studying the nature of metal coordination in various systems owing to its non-degenerate emitting 5D0 state. The paper discusses the photoluminescence of Cu+, Dy3+and Eu3+ in KMgSO4F matrix by a simple method. © 2013 Elsevier B.V.


Manik U.,Sardar Patel Mahavidyalaya | Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2013

The phase formation of the compound Na2Mg(SO4) 2 prepared by a wet chemical method was confirmed by the X-ray powder diffraction (XRD) pattern. Photoluminescence (PL) of Na2Mg(SO 4)2: Ce3+ shows strong emission at 322 nm, and this phosphor is also efficient for Ce3+→ Dy3+ and Ce3+→ Mn2+ energy transfers. The Dy3+ emission by Ce3+→ Dy3+ under UV wavelength is peaking at 475 nm and 572 nm for an excitation of 254 nm due to 4F 9/2 →6H15/2 and 6H 13/2 transitions, whereas Ce3+→Mn2+ is peaking at 515 nm due to 4T1→6A 1 transitions. The Tb3+ emission by Ce3+→ Tb3+ under UV wavelength is peaking at 490, 529, 546 nm, (with a small peak at 586 nm) for the excitation of 352 nm due to 5D 4→7FJ (J=4, 5, 6) transitions. The purpose of the present study is to develop and understand the photoluminescence and effect of Dy3+, Mn2+ or Tb3+ co-doping in Na2Mg(SO4)2:Ce3+ new luminescent materials, which can be the green phosphor in many applications such as lamp phosphors. © 2012 Elsevier B.V.


Poddar A.,Sindhu Mahavidyalaya | Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2014

The phosphors prepared by wet chemical method are studied for their photoluminescence (PL) and thermoluminescence (TL) characteristics. The paper discuses the results on KMgSO4F:Ce halosulfate phosphor co-doped with trivalent rare-earths Dy or Eu which improved luminescence properties. The Dy3+ emission is peaking at 480 nm and 576 nm for an excitation of 390 nm due to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions in blue and yellow-orange region of visible range, whereas Eu3+ is at 590 nm and 612 nm (orange and red region) due to 5D 0→7F1 and 5D 0→7F2 transitions of Eu3+ ion. TL glow curves of KMgSO4F pure, KMgSO4F:Dy, KMgSO 4F:Eu show single peaking at around 154 C, 172 C 180 C, respectively. TL glow curves of KMgSO4F:Ce, Dy show two peaks at the temperatures 202 C and 370 C, whereas KMgSO4F:Ce,Eu shows single peak which is located at around 198 C when they exposed to γ-rays for 5 Gy at the rate of 0.36 kGy h-1. © 2014 Elsevier B.V.


Poddar A.,Sindhu Mahavidyalaya | Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2015

The present KMgCl3 phosphor has been synthesized through wet chemical synthesis (WCS), solid state diffusion (SSD) and Hispersed centrifuge (HC) routes in the same atmospheric conditions and characterized for luminescence properties. XRDs of the sample prepared by all three methods have been placed at the same position, phase and matched well with standard data. The particle size of 20 nm of KMgCl3 by a Hispersed centrifuged method was detected using a transmission electron microscope (TEM). The PL emission spectra have been observed for Ce3+ at 353 nm and 375 nm due to 5d→4f transition, whereas luminescence of Dy3+ efficiently observed at 484 nm and 579 nm for an excitation of 384 nm due to 4F9/2→ 6H15/2 and 6H13/2 (blue-yellow region) transition and Eu3+ is peaking at 596 nm and 616 nm (λex=394 nm) due to level 5D0 to 7Fj (j=0, 1, 2, and 3) radiative transitions. The presented phosphors are excited in the range of 300-400 nm which is mercury free excited range. Synthesis and photoluminescence spectra of trivalent Ce, Dy or Eu rare-earths in KMgCl3 are described for all three routes, for the first time in the present work. The CIE chromaticity coordinates were also calculated for KMgCl3:X (Ce3+, Dy3+ and Eu3+) phosphors, which are close to the NTSC standard values. KMgCl3 matrix is not only suitable for different and easy synthesis but efficient luminescence also. The paper discuses the XRD, crystallinity (morphology) and luminescence of Ce, Dy or Eu rare-earths in KMgCl3 synthesized by three (WCS, SSD and HC) different routes. © 2014 Elsevier B.V. All rights reserved.


Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2013

The thermoluminescence (TL) characteristics and effect of γ-radiation on newly invented NaZnSO4Cl:Ce, Dy or Mn ions and retrapping of charges in TL material prepared by wet chemical method are studied. The sensitivity of the NaZnSO4Cl:Ce, Dy or Mn phosphors is higher than that of CaSO4:Dy with the broadness of the glow peak for various concentrations of Ce, Dy, Mn and different γ-rays doses. The phosphor NaZnSO4Cl:Ce has remarkable high sensitivity as compared to NaZnSO4Cl:Dy or Mn. The phosphors NaZnSO4Cl:Ce, and Mn have a simple TL glow curve structure with a single prominent peak at around the temperature 170 and 190 C, whereas NaZnSO4Cl:Dy has two peaks located at 175 and 298 C indicating single and double trapping sites respectively. TL response, fading and reusability characteristics and the trapping parameters of the phosphor are also studied and it is found that the phosphor is quite suitable for use in dosimetry of ionizing radiations. © 2013 Elsevier B.V.


Choubey S.R.,SRMCEW Nandanvan | Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2013

Dy3+ and Ce3+ emission in NaMg(SO4)F phosphor prepared by the solid state diffusion (SSD) method is reported in this paper. The synthesized phosphors are studied for their photoluminescence (PL) and thermoluminescence (TL) characteristics. The emission spectra of Dy 3+ show dominant peaks at 473 nm and 572 nm for an excitation of 274 nm due to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively, while the emission spectra of Ce3+ peak at 345 nm for an excitation of 254 nm due to the 5d→4f transition of Ce3+. In this host very low concentration of cerium is used. In NaMg(SO 4)F:Dy3+ a single peak is observed at the temperature of 170 C and in NaMg(SO4)F:Ce it is located at 172 C when they are exposed to γ-rays for 5 Gy at the rate of 0.995 kGyh-1. NaMg(SO4)F:Dy is more sensitive whereas, NaMg(SO4)F:Ce less sensitive as compared to standard CaSO4:Dy. NaMg(SO 4)F:Dy phosphor may be useful for TLD application. © 2013 Elsevier B.V.


Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2013

Polycrystalline KCaSO4Cl: (Ce, Dy, Mn and Pb) phosphors prepared by solid state diffusion method have been studied for its trapping parameters by thermoluminescence (TL) phenomenon. The TL glow curves of KCaSO 4Cl: (Ce, Dy, Mn and Pb) phosphor for different concentrations have been recorded at a heating rate of 2 C sec-1 and irradiated at a dose rate of 0.995 kGyh-1 for 5 Gy. The TL glow curves of γ-irradiated KCaSO4Cl: (Ce, Dy, Mn and Pb) phosphors show one glow peak indicating that only one set of traps is being activated within the particular temperature range each with its own value of activation energy (E) and frequency factor (s). The trapping parameters associated with the prominent glow peak of KCaSO4Cl: (Ce, Dy, Mn and Pb) is calculated by using Chen's half width method. The phosphors KCaSO4Cl: Ce, and Pb show first order kinetics while, Dy and Mn show the second order kinetics. The trap depth and frequency factors have been studied subsequently. The release of hole or electron from defect centers at the characteristic trap site initiates the luminescence process in this material. © 2013 Elsevier B.V. All rights reserved.


Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Park K.,Sejong University
Journal of Luminescence | Year: 2013

Newly prepared NaZnSO4Cl chlorosulphate material investigated by a wet chemical method was confirmed by the X-ray powder diffraction (XRD) pattern. Photoluminescence (PL) of NaZnSO4Cl:Ce3+ shows strong emission at 330 nm, and it is also efficient for Ce3+→ Dy3+ and Ce3+→Mn2+ energy transfer for different concentrations. The Dy3+ emission by Ce3+→ Dy3+ under UV wavelength peaking at 473 nm and 573 nm for an excitation of 254 nm due to 4F9/2 →6H 15/2 and 6H13/2 transitions, whereas Ce 3+→Mn2+ is peaking at 515 nm due to 4T1→6A1 transitions. In this phosphor the energy transfer takes place via the resonant process which is dependent on the concentration of the ions. The purpose of the present study is to develop and understand the photoluminescence and effect of Dy3+ or Mn2+ co-doping in NaZnSO4Cl:Ce3+ luminescent material, which can be used as a lamp phosphor. © 2013 Elsevier B.V.

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