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Papers by jagjeet kaur

Physics Letters B, 2011

A new high-performance algorithm for calculating the spin-and parity-dependent shell model nuclea... more A new high-performance algorithm for calculating the spin-and parity-dependent shell model nuclear level densities using methods of statistical spectroscopy in the proton-neutron formalism was recently proposed. When used in valence spaces that cover more than one major harmonic oscillator shell, this algorithm mixes the genuine intrinsic states with spurious center-of-mass excitations. In this paper we present an advanced algorithm, based on the recently proposed statistical moments method, that eliminates the spurious states. Results for unnatural parity states of several sd-shell nuclei are presented and compared with those of exact shell model calculations and experimental data.

Bulletin of Materials Science, 2014

Europium and dysprosium-doped calcium magnesium silicate powder with different concentrations of ... more Europium and dysprosium-doped calcium magnesium silicate powder with different concentrations of dysprosium were synthesized using solid-state reaction. The Fourier transform infrared (FT-IR) spectra confirmed the proper preparation of the sample. The prepared phosphors were characterized using photoluminescence excitation and emission spectra. Prominent green colour emission was obtained under ultraviolet excitation. The thermoluminescence glow curves of the samples were measured at various delay times. With increased delay time, the intensity of the thermoluminescence peak decays and the position of the thermoluminescence peak shifts towards higher temperature, indicating the considerable retrapping associated with general order kinetics.

This paper reports the Thermoluminescence properties of Eu doped yttrium zirconate phosphor. The ... more This paper reports the Thermoluminescence properties of Eu doped yttrium zirconate phosphor. The phosphor is synthesized by solid state reaction method. This method is suitable for large scale production. Starting materials used for sample preparation are Y2O3, ZrO2, Eu2O3 and fixed concentration of boric acid using as a flux. The prepared phosphors for different concentration of Eu 3+ were examined by Thermoluminescence (TL) glow curve for fix UV irradiation. For UV irradiation UV 254 nm source was used. The kinetic parameters such as activation energy, order of kinetics and frequency factor were calculated by peak shape method. Most of the peak shows general order kinetics. The effect of UV exposure on TL studies was examined and it shows linear response with dose that indicates the sample may be useful for TL dosimeter. Keywords— Solid state reaction; Thermoluminescence; yttrium zirconate.

Luminescence, 2021

Herein, we have reported the photoluminescent and thermoluminescent properties of Dy activated Ca... more Herein, we have reported the photoluminescent and thermoluminescent properties of Dy activated Ca2 ZnSi2 O7 phosphors synthesized via the solid-state method. The synthesized phosphors showed hardystonite type structure, and had micron sized particles. Fourier transform infrared spectroscopy (FTIR) showed the existence of the functional groups and confirmed the formation of phosphor and photoluminescent techniques. The phosphors under excitation at 239 nm exhibited green-yellow emission spectra in the region of 481-575 nm corresponding to the 4 F9/2 →6 H15/2 and 4 F9/2 →6 H13/2 transitions of Dy3+ ions. The Commission Internationale de l'Eclairage (CIE) coordinates were achieved to be (0.25, 0.27), which was narrowly close to the white region. Thermoluminescence (TL) glow curve analysis of prepared Dy3+ -activated Ca2 ZnSi2 O7 phosphors were recorded for different UV exposure time and found linear response with dose. The TL glow curves, recorded with various UV exposure time ranging from 5 to 25 min, showed linear response with dosage. The corresponding kinetic parameters were also calculated using Computerized Glow Curve Deconvolution (CGCD) technique. Activation energy was observed to enhance with the increase of the peak temperature and its value was substantially high for the third peak fitted by CGCD. The obtained results indicated that the synthesized pristine phosphors could be potential for lighting, displays and dosimetric applications.

Radiation Effects and Defects in Solids, 2017

Herein the manuscript reports kinetics and Thermoluminescence (TL) glow curve analysis of UV-, βa... more Herein the manuscript reports kinetics and Thermoluminescence (TL) glow curve analysis of UV-, βand γ-irradiated natural limestone samples collected from Chunkatta mines of Chhattisgarh basin. The collected samples were annealed at 100°C for 1 h for preheat treatment before irradiation after that the samples were irradiated by UV, β and γ , respectively. After irradiation the 1 mg weigh samples perform for TL glow curve analysis. Collected limestone was characterized by X-ray diffraction analysis technique and crystallite size was calculated using Scherer's formula. UV-irradiated sample shows the high-temperature peak centered at 250°C, for β-irradiated sample showed well resolved broad TL glow curve at 404 K which is fitted using computerized glow curve deconvolution (CGCD) technique. Similarly, for γ-irradiation the well resolved three distinct peaks at 209, 288 and 388°C showed the formation of deep trapping for γirradiation. Dose rate effect for UV-and γ-irradiation reported in details as well as the trap formation were described by trap depth model. Kinetic parameters for UV-, βand γ-irradiation were calculated using peak shape method by CGCD technique. The study was determined the trap level formation and application related to TL dose response in collected limestone sample.

Optik, 2016

This paper reports synthesis of Ce 3+ ions-doped Gd 2 SiO 5 phosphor powders prepared by modified... more This paper reports synthesis of Ce 3+ ions-doped Gd 2 SiO 5 phosphor powders prepared by modified solid state reaction method, which is most suitable method for large-scale production. Starting materials used for sample preparation were Gd 2 O 3 , SiO 2 and CeO 2 with variable concentration of cerium (0.1 mol% to 2.5 mol%) with fixed amount of boric acid (0.05 mol%) as flux. PL excitation spectra was found at 260 nm while the emission spectra was found at 365, 378, 555, 602, 607 and 627 nm for lower Ce 3+ doping concentration which are attributed to the Gd 3+ ion transitions. For higher concentration of Ce 3+ we get broad emission spectra from 350 to 550 nm which is characteristics of Ce 3+ ion transition. Commission Internationale de l'Eclairage coordinate (CIE) of this phosphor is x = 0.170, y = 0.029, in the violet region for 2.5 mol% of cerium. TL glow curves were recorded for different doses of UV exposure and gamma ray dose at a heating rate of 5 • C s −1. The kinetic parameters such as activation energy "E", the order of kinetics "b", and the frequency factor "s" of Gd 2 SiO 5 :Ce 3+ have been calculated by using peak shape method. Sample shows general order kinetics for most of the peaks. The effect of Ce 3+ concentration on TL intensity was also studied and found that the intensity is maximum for 0.1 mol% and then decreases with increasing concentration of Ce 3+. The present phosphor can acts as a single host for violetblue emission (2.5 mol%) for display devices as well as may be used for thermoluminescence dosimetric material under UV & gamma dose.

Journal of Display Technology, 2016

Di-barium magnesium silicate doped with Eu 2+^{2+}2+ and Tm 3+^{3+}3+ phosphors were prepared for dif... more Di-barium magnesium silicate doped with Eu 2+^{2+}2+ and Tm 3+^{3+}3+ phosphors were prepared for different concentrations of Tm 3+^{3+}3+ ions keeping the concentration of Eu 2+^{2+}2+ as 0.5 mol%. Photoluminescence (PL) studies of prepared samples were carried out. Emission spectra exhibited optimum green color emission at 509 nm when Tm 3+^{3+}3+ was 1.5 mol%. Emission is expected to arise due to the transition of Eu 2+^{2+}2+ ions from any of the sublevels of 4d 6^{6}6 5f 1^{1}1 to its ground state ( 8{}^{8}8 S 7/2)_{7/2})7/2) . This sample with 1.5 mol% of Tm 3+^{3+}3+ is taken for X-ray diffraction analysis. XRD pattern confirmed that the sample follows monoclinic structure with C 1 2/c 1 (15) space group. Scanning Electron Microscope image of the sample exhibited the uniform morphology with average particle size of 222.54 mu\mumu m . Thermoluminescence (TL) glow curves of the sample for different UV irradiation were also recorded which presented single broaden peak centered at about hbox91circ{\hbox{91}}\ ^{\circ}hbox91circ C. Phosphorescence decay curve was indicative of presence of dual exponential decaying section with a fast decay followed by a long decaying part.

Research on Chemical Intermediates, 2015

This paper reports thermoluminescence (TL) properties of Ce3+ doped yttrium silicate phosphor. Th... more This paper reports thermoluminescence (TL) properties of Ce3+ doped yttrium silicate phosphor. The phosphor is synthesized by a solid state reaction method which is suitable for large scale production. Starting materials used for sample preparation were Y2O3, SiO2, CeO2 and a fixed concentration of boric acid used as a flux. The prepared phosphors for different concentrations of Ce3+ were examined by observing their TL glow curves for UV irradiation (254-nm source). The samples show a well resolved broad peak covering a temperature range of 50–375 °C. The kinetic parameters such as activation energy, order of kinetics and frequency factor were calculated by the peak shape method. Most of the peaks show general order kinetics. The effect of UV exposure on TL was also examined and a linear response to dose was shown, indicating the sample may be useful for a TL dosimeter. The kinetic parameters were calculated using a computerized glow curve de-convolution (CGCD) technique.

Journal of Minerals and Materials Characterization and Engineering, 2010

Behavior displayed by a thermoluminescence (TL) glow peak as radiation dose increases in limeston... more Behavior displayed by a thermoluminescence (TL) glow peak as radiation dose increases in limestone of Patharia mines of Chhattisgarh in India { Location : Durg (dist.) Elevation 274 meters, E 81 o 22' 48" N-21 o 23' 40.5'' way point 196} have been reported. The glow curve of Limestone peak is observed at 306.1 0 C & slightly shifting of peak is observed at low temperature side. The value of activation energy and order of kinetics for 306.1 o C peak suggest low fading & high stability.

Superlattices and Microstructures, 2015

Present paper reports the preparation of Sr 2 MgSi 2 O 7 doped with Dy 3+ ions by modified high t... more Present paper reports the preparation of Sr 2 MgSi 2 O 7 doped with Dy 3+ ions by modified high temperature solid state reaction technique. Samples were prepared for different concentration of Dy 3+ (0.5, 1.0, 1.5, 2.0 and 2.5 mol%). Sample with optimum photoluminescence intensity was characterized by X-ray diffraction (XRD) technique. Observed XRD spectrum matched with crystallographic open database card specifically appeared for Sr 2 MgSi 2 O 7 phosphor. This is a confirmation of proper preparation of the sample. Photoluminescence studies of these samples were done. Emission spectra exhibited 5 prominent peaks at 480, 490, 575, 590 and 660 nm respectively. In this case Dy 3+ acts as an activator. Peaks centered at 480 and 490 nm are due to the transition 4 F 9/2 ? 6 H 15/2 (blue color) of Dy 3+ ions occupied at different sites. Similarly 575 and 590 nm peaks are originated due to transition 4 F 9/2 ? 6 H 13/2 (yellow-orange color) of Dy 3+ ions occupied at different sites. Emission at 660 nm is due to transition 4 F 9/2 ? 6 H 11/2 (red color). CIE coordinates have been calculated for each sample and its value exhibited that, overall emission is near white light. In order to investigate the suitability of the samples as white color light sources for industrial uses, correlated color temperature (CCT) and color rendering index (CRI) were calculated. Values of CCT and CRI were found, well within the defined acceptable range.

Journal of Radiation Research and Applied Sciences, 2015

Di strontium magnesium silicate phosphor doped with specific concentration of Eu 2þ (0.5 mol%) an... more Di strontium magnesium silicate phosphor doped with specific concentration of Eu 2þ (0.5 mol%) and Dy 3þ (1.5 mol%) is prepared using solid state reaction technique. Sample was characterized by X-ray diffraction (XRD) and Fourier transforms infrared techniques. Scanning Electron Microscopy was done to see the morphology of prepared sample. Refined lattice parameters and bond lengths were calculated using the refined data. Mechanoluminescence (ML) studies were also done. Sample exhibited fairly good ML properties. ML spectra expressed single peak supports the formation of single emission centre due to transition of Eu 2þ ions due to transitions from any of the sublevels of 4f 6 5 d 1 configuration to 8 S 7/2 level of the 4f 7 configuration. Semi-log plots of ML were used to calculate ML decay constant. Calculated ML decay constant indicated that it has slow decay which is one of the properties of long lasting phosphors. It was considered that formation of new surface comprising of local and bulk piezoelectricity are responsible for ML emission. This fracto-mechanoluminescent material can be used in the devices like fracture sensor, impact sensor, damage sensors, safety management monitoring system, fuse system for army warheads, etc.

Research on Chemical Intermediates, 2014

The present paper reports the synthesis, photoluminescence (PL), and thermoluminescence (TL) stud... more The present paper reports the synthesis, photoluminescence (PL), and thermoluminescence (TL) studies of Eu 3?-doped yttrium oxide (Y 2 O 3) phosphor using inorganic materials like Y 2 O 3 , flux calcium fluoride, and europium oxide. The sample was prepared by the modified solid state reaction method, which is the most suitable for large-scale production. The prepared phosphor sample was characterized using powder X-ray diffraction, field emission gun scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy , PL, TL, and Commission Internationale de I'Eclairage techniques. The PL emission was observed in the range 417-632 nm ranges all visible regions for the Y 2 O 3 phosphor doped with Eu 3?. Excitation spectrum found at 254 nm. Sharp intense peaks found around 467, 534, 594, 612, and 632 nm with high intensity. From the XRD data, using the Scherer's formula, the calculated average crystallite size of Eu 3?doped Y 2 O 3 phosphor is around 45 nm. TL study was carried out for the phosphor with UV irradiation. The present phosphor can act as single host for white light emission in display devices.

Research on Chemical Intermediates, 2013

Abstract This paper reports thermoluminescence glow curves of Eu 3+, Dy 3+-doped Ba 2 MgSi 2 O 7 ... more Abstract This paper reports thermoluminescence glow curves of Eu 3+, Dy 3+-doped Ba 2 MgSi 2 O 7 phosphor for different UV exposure times. Kinetic data were evaluated by the peak-shape method. The glow curves shift toward higher intensity with increasing exposure time to UV at 365 nm. When the heating rate was 5 C s− 1, peaks were observed at 101.76, 109.69, 102.67, and 104.05 C, respectively, after UV exposure for 5, 10, 15, and 20 min. The glow peaks are indicative of second-order kinetics. Different kinetic data, ie trap depth, ...

Research on Chemical Intermediates, 2013

Abstract This paper reports TL glow curve analysis and evaluation of kinetic parameter for Amarna... more Abstract This paper reports TL glow curve analysis and evaluation of kinetic parameter for Amarnath stone collected from Amarnath Holy Cave. TL was recorded with different heating rates (3.3, 4, 6.7, 8, and 10 s− 1). The samples gave good TL peaks at 310, 314, 308, 323, and 327 C for the different heating rates. The corresponding activation energy (E) values were calculated. The peaks were indicative of second-order kinetics. Samples were characterized by XRD analysis. Inductively coupled plasma activated emission ...

Research on Chemical Intermediates, 2013

ABSTRACT The present review deals with the synthesis and characterization of different phosphors ... more ABSTRACT The present review deals with the synthesis and characterization of different phosphors used in medical imaging. A comparative study of different synthesis methods and characterization is presented. The best method for synthesized phosphor is the solid state method because the morphology of the sample is very good. The photostimulated luminescence of the prepared sample has been represented by different authors. The best phosphor used in medical imaging is BaBrCl:Eu2+.

Research on Chemical Intermediates, 2012

Abstract This paper reports the mechanoluminescence (ML) and photoluminescence (PL) spectra of (Z... more Abstract This paper reports the mechanoluminescence (ML) and photoluminescence (PL) spectra of (Zn, Cd) S: Mn,(Zn, Cd) S: Cu,(Zn, Cd) S: Ag, and (Zn, Cd) S: Au mixed phosphors. The PL spectra of the phosphors were similar to the ML spectra within the limit of experimental error. For (Zn, Cd) S: Cu,(Zn, Cd) S: Ag, and (Zn, Cd) S: Au phosphors ML spectra shifted toward lower wavelength compared with PL spectra whereas for the Mn-doped (Zn, Cd) S phosphor ML spectra shifted toward higher wavelength compared with ...

Research on Chemical Intermediates, 2013

ABSTRACT This review includes research papers on different methods of preparation of Eu2+ and Dy3... more ABSTRACT This review includes research papers on different methods of preparation of Eu2+ and Dy3+-doped SrAl2O4 phosphors and papers reporting luminescence studies of the materials. The methods of preparation were compared and it was concluded that solid state reaction is the best method. Papers on characterization of these phosphors by X-ray diffraction and scanning electron microscopy are also discussed. The review ends with a few important conclusions.

Journal of Interdisciplinary Mathematics, 2010

ABSTRACT If p(z) be a polynomial of degree n having no zeros in the disk |z| < 1 , then it... more ABSTRACT If p(z) be a polynomial of degree n having no zeros in the disk |z| < 1 , then it is well known that

Journal of Interdisciplinary Mathematics, 2012

ABSTRACT It was shown by Ankeny and Rivlin that if p (z) is a polynomial of degree n having no ze... more ABSTRACT It was shown by Ankeny and Rivlin that if p (z) is a polynomial of degree n having no zero in | z |< 1, then

Physics Letters B, 2011

A new high-performance algorithm for calculating the spin-and parity-dependent shell model nuclea... more A new high-performance algorithm for calculating the spin-and parity-dependent shell model nuclear level densities using methods of statistical spectroscopy in the proton-neutron formalism was recently proposed. When used in valence spaces that cover more than one major harmonic oscillator shell, this algorithm mixes the genuine intrinsic states with spurious center-of-mass excitations. In this paper we present an advanced algorithm, based on the recently proposed statistical moments method, that eliminates the spurious states. Results for unnatural parity states of several sd-shell nuclei are presented and compared with those of exact shell model calculations and experimental data.

Bulletin of Materials Science, 2014

Europium and dysprosium-doped calcium magnesium silicate powder with different concentrations of ... more Europium and dysprosium-doped calcium magnesium silicate powder with different concentrations of dysprosium were synthesized using solid-state reaction. The Fourier transform infrared (FT-IR) spectra confirmed the proper preparation of the sample. The prepared phosphors were characterized using photoluminescence excitation and emission spectra. Prominent green colour emission was obtained under ultraviolet excitation. The thermoluminescence glow curves of the samples were measured at various delay times. With increased delay time, the intensity of the thermoluminescence peak decays and the position of the thermoluminescence peak shifts towards higher temperature, indicating the considerable retrapping associated with general order kinetics.

This paper reports the Thermoluminescence properties of Eu doped yttrium zirconate phosphor. The ... more This paper reports the Thermoluminescence properties of Eu doped yttrium zirconate phosphor. The phosphor is synthesized by solid state reaction method. This method is suitable for large scale production. Starting materials used for sample preparation are Y2O3, ZrO2, Eu2O3 and fixed concentration of boric acid using as a flux. The prepared phosphors for different concentration of Eu 3+ were examined by Thermoluminescence (TL) glow curve for fix UV irradiation. For UV irradiation UV 254 nm source was used. The kinetic parameters such as activation energy, order of kinetics and frequency factor were calculated by peak shape method. Most of the peak shows general order kinetics. The effect of UV exposure on TL studies was examined and it shows linear response with dose that indicates the sample may be useful for TL dosimeter. Keywords— Solid state reaction; Thermoluminescence; yttrium zirconate.

Luminescence, 2021

Herein, we have reported the photoluminescent and thermoluminescent properties of Dy activated Ca... more Herein, we have reported the photoluminescent and thermoluminescent properties of Dy activated Ca2 ZnSi2 O7 phosphors synthesized via the solid-state method. The synthesized phosphors showed hardystonite type structure, and had micron sized particles. Fourier transform infrared spectroscopy (FTIR) showed the existence of the functional groups and confirmed the formation of phosphor and photoluminescent techniques. The phosphors under excitation at 239 nm exhibited green-yellow emission spectra in the region of 481-575 nm corresponding to the 4 F9/2 →6 H15/2 and 4 F9/2 →6 H13/2 transitions of Dy3+ ions. The Commission Internationale de l'Eclairage (CIE) coordinates were achieved to be (0.25, 0.27), which was narrowly close to the white region. Thermoluminescence (TL) glow curve analysis of prepared Dy3+ -activated Ca2 ZnSi2 O7 phosphors were recorded for different UV exposure time and found linear response with dose. The TL glow curves, recorded with various UV exposure time ranging from 5 to 25 min, showed linear response with dosage. The corresponding kinetic parameters were also calculated using Computerized Glow Curve Deconvolution (CGCD) technique. Activation energy was observed to enhance with the increase of the peak temperature and its value was substantially high for the third peak fitted by CGCD. The obtained results indicated that the synthesized pristine phosphors could be potential for lighting, displays and dosimetric applications.

Radiation Effects and Defects in Solids, 2017

Herein the manuscript reports kinetics and Thermoluminescence (TL) glow curve analysis of UV-, βa... more Herein the manuscript reports kinetics and Thermoluminescence (TL) glow curve analysis of UV-, βand γ-irradiated natural limestone samples collected from Chunkatta mines of Chhattisgarh basin. The collected samples were annealed at 100°C for 1 h for preheat treatment before irradiation after that the samples were irradiated by UV, β and γ , respectively. After irradiation the 1 mg weigh samples perform for TL glow curve analysis. Collected limestone was characterized by X-ray diffraction analysis technique and crystallite size was calculated using Scherer's formula. UV-irradiated sample shows the high-temperature peak centered at 250°C, for β-irradiated sample showed well resolved broad TL glow curve at 404 K which is fitted using computerized glow curve deconvolution (CGCD) technique. Similarly, for γ-irradiation the well resolved three distinct peaks at 209, 288 and 388°C showed the formation of deep trapping for γirradiation. Dose rate effect for UV-and γ-irradiation reported in details as well as the trap formation were described by trap depth model. Kinetic parameters for UV-, βand γ-irradiation were calculated using peak shape method by CGCD technique. The study was determined the trap level formation and application related to TL dose response in collected limestone sample.

Optik, 2016

This paper reports synthesis of Ce 3+ ions-doped Gd 2 SiO 5 phosphor powders prepared by modified... more This paper reports synthesis of Ce 3+ ions-doped Gd 2 SiO 5 phosphor powders prepared by modified solid state reaction method, which is most suitable method for large-scale production. Starting materials used for sample preparation were Gd 2 O 3 , SiO 2 and CeO 2 with variable concentration of cerium (0.1 mol% to 2.5 mol%) with fixed amount of boric acid (0.05 mol%) as flux. PL excitation spectra was found at 260 nm while the emission spectra was found at 365, 378, 555, 602, 607 and 627 nm for lower Ce 3+ doping concentration which are attributed to the Gd 3+ ion transitions. For higher concentration of Ce 3+ we get broad emission spectra from 350 to 550 nm which is characteristics of Ce 3+ ion transition. Commission Internationale de l'Eclairage coordinate (CIE) of this phosphor is x = 0.170, y = 0.029, in the violet region for 2.5 mol% of cerium. TL glow curves were recorded for different doses of UV exposure and gamma ray dose at a heating rate of 5 • C s −1. The kinetic parameters such as activation energy "E", the order of kinetics "b", and the frequency factor "s" of Gd 2 SiO 5 :Ce 3+ have been calculated by using peak shape method. Sample shows general order kinetics for most of the peaks. The effect of Ce 3+ concentration on TL intensity was also studied and found that the intensity is maximum for 0.1 mol% and then decreases with increasing concentration of Ce 3+. The present phosphor can acts as a single host for violetblue emission (2.5 mol%) for display devices as well as may be used for thermoluminescence dosimetric material under UV & gamma dose.

Journal of Display Technology, 2016

Di-barium magnesium silicate doped with Eu 2+^{2+}2+ and Tm 3+^{3+}3+ phosphors were prepared for dif... more Di-barium magnesium silicate doped with Eu 2+^{2+}2+ and Tm 3+^{3+}3+ phosphors were prepared for different concentrations of Tm 3+^{3+}3+ ions keeping the concentration of Eu 2+^{2+}2+ as 0.5 mol%. Photoluminescence (PL) studies of prepared samples were carried out. Emission spectra exhibited optimum green color emission at 509 nm when Tm 3+^{3+}3+ was 1.5 mol%. Emission is expected to arise due to the transition of Eu 2+^{2+}2+ ions from any of the sublevels of 4d 6^{6}6 5f 1^{1}1 to its ground state ( 8{}^{8}8 S 7/2)_{7/2})7/2) . This sample with 1.5 mol% of Tm 3+^{3+}3+ is taken for X-ray diffraction analysis. XRD pattern confirmed that the sample follows monoclinic structure with C 1 2/c 1 (15) space group. Scanning Electron Microscope image of the sample exhibited the uniform morphology with average particle size of 222.54 mu\mumu m . Thermoluminescence (TL) glow curves of the sample for different UV irradiation were also recorded which presented single broaden peak centered at about hbox91circ{\hbox{91}}\ ^{\circ}hbox91circ C. Phosphorescence decay curve was indicative of presence of dual exponential decaying section with a fast decay followed by a long decaying part.

Research on Chemical Intermediates, 2015

This paper reports thermoluminescence (TL) properties of Ce3+ doped yttrium silicate phosphor. Th... more This paper reports thermoluminescence (TL) properties of Ce3+ doped yttrium silicate phosphor. The phosphor is synthesized by a solid state reaction method which is suitable for large scale production. Starting materials used for sample preparation were Y2O3, SiO2, CeO2 and a fixed concentration of boric acid used as a flux. The prepared phosphors for different concentrations of Ce3+ were examined by observing their TL glow curves for UV irradiation (254-nm source). The samples show a well resolved broad peak covering a temperature range of 50–375 °C. The kinetic parameters such as activation energy, order of kinetics and frequency factor were calculated by the peak shape method. Most of the peaks show general order kinetics. The effect of UV exposure on TL was also examined and a linear response to dose was shown, indicating the sample may be useful for a TL dosimeter. The kinetic parameters were calculated using a computerized glow curve de-convolution (CGCD) technique.

Journal of Minerals and Materials Characterization and Engineering, 2010

Behavior displayed by a thermoluminescence (TL) glow peak as radiation dose increases in limeston... more Behavior displayed by a thermoluminescence (TL) glow peak as radiation dose increases in limestone of Patharia mines of Chhattisgarh in India { Location : Durg (dist.) Elevation 274 meters, E 81 o 22' 48" N-21 o 23' 40.5'' way point 196} have been reported. The glow curve of Limestone peak is observed at 306.1 0 C & slightly shifting of peak is observed at low temperature side. The value of activation energy and order of kinetics for 306.1 o C peak suggest low fading & high stability.

Superlattices and Microstructures, 2015

Present paper reports the preparation of Sr 2 MgSi 2 O 7 doped with Dy 3+ ions by modified high t... more Present paper reports the preparation of Sr 2 MgSi 2 O 7 doped with Dy 3+ ions by modified high temperature solid state reaction technique. Samples were prepared for different concentration of Dy 3+ (0.5, 1.0, 1.5, 2.0 and 2.5 mol%). Sample with optimum photoluminescence intensity was characterized by X-ray diffraction (XRD) technique. Observed XRD spectrum matched with crystallographic open database card specifically appeared for Sr 2 MgSi 2 O 7 phosphor. This is a confirmation of proper preparation of the sample. Photoluminescence studies of these samples were done. Emission spectra exhibited 5 prominent peaks at 480, 490, 575, 590 and 660 nm respectively. In this case Dy 3+ acts as an activator. Peaks centered at 480 and 490 nm are due to the transition 4 F 9/2 ? 6 H 15/2 (blue color) of Dy 3+ ions occupied at different sites. Similarly 575 and 590 nm peaks are originated due to transition 4 F 9/2 ? 6 H 13/2 (yellow-orange color) of Dy 3+ ions occupied at different sites. Emission at 660 nm is due to transition 4 F 9/2 ? 6 H 11/2 (red color). CIE coordinates have been calculated for each sample and its value exhibited that, overall emission is near white light. In order to investigate the suitability of the samples as white color light sources for industrial uses, correlated color temperature (CCT) and color rendering index (CRI) were calculated. Values of CCT and CRI were found, well within the defined acceptable range.

Journal of Radiation Research and Applied Sciences, 2015

Di strontium magnesium silicate phosphor doped with specific concentration of Eu 2þ (0.5 mol%) an... more Di strontium magnesium silicate phosphor doped with specific concentration of Eu 2þ (0.5 mol%) and Dy 3þ (1.5 mol%) is prepared using solid state reaction technique. Sample was characterized by X-ray diffraction (XRD) and Fourier transforms infrared techniques. Scanning Electron Microscopy was done to see the morphology of prepared sample. Refined lattice parameters and bond lengths were calculated using the refined data. Mechanoluminescence (ML) studies were also done. Sample exhibited fairly good ML properties. ML spectra expressed single peak supports the formation of single emission centre due to transition of Eu 2þ ions due to transitions from any of the sublevels of 4f 6 5 d 1 configuration to 8 S 7/2 level of the 4f 7 configuration. Semi-log plots of ML were used to calculate ML decay constant. Calculated ML decay constant indicated that it has slow decay which is one of the properties of long lasting phosphors. It was considered that formation of new surface comprising of local and bulk piezoelectricity are responsible for ML emission. This fracto-mechanoluminescent material can be used in the devices like fracture sensor, impact sensor, damage sensors, safety management monitoring system, fuse system for army warheads, etc.

Research on Chemical Intermediates, 2014

The present paper reports the synthesis, photoluminescence (PL), and thermoluminescence (TL) stud... more The present paper reports the synthesis, photoluminescence (PL), and thermoluminescence (TL) studies of Eu 3?-doped yttrium oxide (Y 2 O 3) phosphor using inorganic materials like Y 2 O 3 , flux calcium fluoride, and europium oxide. The sample was prepared by the modified solid state reaction method, which is the most suitable for large-scale production. The prepared phosphor sample was characterized using powder X-ray diffraction, field emission gun scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy , PL, TL, and Commission Internationale de I'Eclairage techniques. The PL emission was observed in the range 417-632 nm ranges all visible regions for the Y 2 O 3 phosphor doped with Eu 3?. Excitation spectrum found at 254 nm. Sharp intense peaks found around 467, 534, 594, 612, and 632 nm with high intensity. From the XRD data, using the Scherer's formula, the calculated average crystallite size of Eu 3?doped Y 2 O 3 phosphor is around 45 nm. TL study was carried out for the phosphor with UV irradiation. The present phosphor can act as single host for white light emission in display devices.

Research on Chemical Intermediates, 2013

Abstract This paper reports thermoluminescence glow curves of Eu 3+, Dy 3+-doped Ba 2 MgSi 2 O 7 ... more Abstract This paper reports thermoluminescence glow curves of Eu 3+, Dy 3+-doped Ba 2 MgSi 2 O 7 phosphor for different UV exposure times. Kinetic data were evaluated by the peak-shape method. The glow curves shift toward higher intensity with increasing exposure time to UV at 365 nm. When the heating rate was 5 C s− 1, peaks were observed at 101.76, 109.69, 102.67, and 104.05 C, respectively, after UV exposure for 5, 10, 15, and 20 min. The glow peaks are indicative of second-order kinetics. Different kinetic data, ie trap depth, ...

Research on Chemical Intermediates, 2013

Abstract This paper reports TL glow curve analysis and evaluation of kinetic parameter for Amarna... more Abstract This paper reports TL glow curve analysis and evaluation of kinetic parameter for Amarnath stone collected from Amarnath Holy Cave. TL was recorded with different heating rates (3.3, 4, 6.7, 8, and 10 s− 1). The samples gave good TL peaks at 310, 314, 308, 323, and 327 C for the different heating rates. The corresponding activation energy (E) values were calculated. The peaks were indicative of second-order kinetics. Samples were characterized by XRD analysis. Inductively coupled plasma activated emission ...

Research on Chemical Intermediates, 2013

ABSTRACT The present review deals with the synthesis and characterization of different phosphors ... more ABSTRACT The present review deals with the synthesis and characterization of different phosphors used in medical imaging. A comparative study of different synthesis methods and characterization is presented. The best method for synthesized phosphor is the solid state method because the morphology of the sample is very good. The photostimulated luminescence of the prepared sample has been represented by different authors. The best phosphor used in medical imaging is BaBrCl:Eu2+.

Research on Chemical Intermediates, 2012

Abstract This paper reports the mechanoluminescence (ML) and photoluminescence (PL) spectra of (Z... more Abstract This paper reports the mechanoluminescence (ML) and photoluminescence (PL) spectra of (Zn, Cd) S: Mn,(Zn, Cd) S: Cu,(Zn, Cd) S: Ag, and (Zn, Cd) S: Au mixed phosphors. The PL spectra of the phosphors were similar to the ML spectra within the limit of experimental error. For (Zn, Cd) S: Cu,(Zn, Cd) S: Ag, and (Zn, Cd) S: Au phosphors ML spectra shifted toward lower wavelength compared with PL spectra whereas for the Mn-doped (Zn, Cd) S phosphor ML spectra shifted toward higher wavelength compared with ...

Research on Chemical Intermediates, 2013

ABSTRACT This review includes research papers on different methods of preparation of Eu2+ and Dy3... more ABSTRACT This review includes research papers on different methods of preparation of Eu2+ and Dy3+-doped SrAl2O4 phosphors and papers reporting luminescence studies of the materials. The methods of preparation were compared and it was concluded that solid state reaction is the best method. Papers on characterization of these phosphors by X-ray diffraction and scanning electron microscopy are also discussed. The review ends with a few important conclusions.

Journal of Interdisciplinary Mathematics, 2010

ABSTRACT If p(z) be a polynomial of degree n having no zeros in the disk |z| < 1 , then it... more ABSTRACT If p(z) be a polynomial of degree n having no zeros in the disk |z| < 1 , then it is well known that

Journal of Interdisciplinary Mathematics, 2012

ABSTRACT It was shown by Ankeny and Rivlin that if p (z) is a polynomial of degree n having no ze... more ABSTRACT It was shown by Ankeny and Rivlin that if p (z) is a polynomial of degree n having no zero in | z |< 1, then