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Dahire S.L.,Sindhu Mahavidyalaya | Morey Y.C.,Hislop College | Agrawal P.S.,Laxminarayan Institute of Technology
Russian Journal of Physical Chemistry A | Year: 2015

Density (ρ), viscosity (η), and ultrasonic velocity (U) of binary mixtures of aliphatic solvents like dimethylformamide (DMF) and dimethylsulfoxide (DMSO) with aromatic solvents viz. chlorobenzene (CB), bromobenzene (BB), and nitrobenzene (NB) have been determined at 313 K. These parameters were used to calculate the adiabatic compressibility (β), intermolecular free length (L f), molar volume (V m), and acoustic impedance (Z). From the experimental data excess molar volume (V m E), excess intermolecular free length (L f E)), excess adiabatic compressibility (βE), and excess acoustic impedance (Z E) have been computed. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations (σ). © 2015 Pleiades Publishing, Ltd. Source


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. Source


Poddar A.,Sindhu Mahavidyalaya | Gedam S.C.,Kzs Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Radiation Effects and Defects in Solids | Year: 2015

New halophosphor K3Ca2(SO4)3F activated by Eu and Ce has been synthesized by a co-precipitation method and characterized according to its thermoluminescence. The formation of traps in rare earth doped K3Ca2(SO4)3F and the effects of γ-radiation dose on the glow curve are discussed. The glow curve of K3Ca2(SO4)3F:Ce shows a prominent single peak at 150°C, whereas K3Ca2(SO4)3F:Eu and K3a2(SO4)3F:Ce,Eu at 142°C and 192°C, respectively. A single glow peak indicates that there is only one set of trap being activated within the particular temperature range. The presented phosphors are also studied because of its fading, reusability and trapping parameters. There was just 2% fading during a period of 10 days, indicating no serious fading problem. Trapping parameters such as order of kinetics (b), activation energy (E) and frequency factor (S) were calculated by using Chen's half-width method. The observations presented in this paper are good for lamp phosphors as well as solid-state dosimeter. © 2015 © 2015 Taylor & Francis. Source


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

KMgSO4F:Ce and KMgSO4F:Mn phosphors were prepared by a wet chemical method and studied for their photoluminescence (PL) and thermoluminescence (TL) characteristics. PL emission of KMgSO4F:Ce peaked at around 440 nm for the excitation at 377 nm due to 5d → 4f transition, while KMgSO4F:Mn had a peak at 540 nm for an excitation at 363 nm and 247 nm due to 4T1g → 6A1g transition. The phosphors also showed good thermoluminescence characteristics when they were exposed to γ-rays at a 5 Gy dose at the rate of 0.36 kGyh-1. KMgSO4F:Ce exhibited a single thermoluminescence (TL) peak at around 167 °C and KMgSO4F:Mn also exhibited a single TL peak at around 177 °C. Possible trapping parameters such as order of kinetics (b), the geometrical factor (μg), the frequency factor (s) and the activation energy were also evaluated by Chen's half width method. This article discusses fundamental PL and TL characteristics in inorganic fluoride material activated by Ce3+ and Mn2+ ions and prepared by a wet chemical method. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd. Source


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. Source

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