Indian Journal of Pure and Applied Physics

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VOLUME 47

NUMBER 6

JUNE 2009

CODEN:IJOPAU 47(6) 391-466

 

ISSN:0019-5596

 

                                                                      Special Issue

 

                                                                               on

 

                                     Luminescence and its Applications

 

                             (This special issue is based on the papers presented at International Conference on Luminescence and its
                             Applications held at National Physical Laboratory, New Delhi during February 13-16, 2008)

 

                                                                      CONTENTS

 

Foreword

393

        V S Ramamurthy

 

 

 

Preface

395

        Vikram Kumar  &  Santa Chawla  

 

 

 

Papers  

 

 

 

Development of plasma display panel phosphors at National Physical Laboratory, New Delhi

399

        R S Yadav, A F Khan, Harish Chander, D Haranath, Ashish Yadav, A K Sharma & Santa Chawla*  

 

 

Effect of heating rate on TL glow curves — Theoretical and experimental studies

402

        Munish Kumar*, G Chourasiya, R K Kher, B C Bhatt & C M Sunta  

 

 

 

Trap spectroscopy of microcline in the temperature range 77-600 K

406

        K Bishal Singh, A B Ahmed & R K Gartia*  

 

 

 

Kinetic parameters of thermoluminescence glow curves of g-irradiated green calcite

409

        T Dwijen Singh & S Dorendrajit Singh*  

 

 

Effect of temperature of optical stimulation on thermoluminescence peak of synthetic

quartz

413

        Y D Kale* & Y H Gandhi  

 

 

Analysis of glow curves of quartz and transluminescence dating

417

        R K Gartia*, L Lovedy & U Ranita  

 

 

 

Role of defect centres in thermoluminescence mechanism of Tb3+doped MgAl2O4

420

        E Alagu Raja*, Bhushan Dhabekar, Sanjeev Menon, S P More, T K Gundu Rao & R K Kher  

 

 

 

Thermoluminescence, optically stimulated luminescence and ESR studies on LiAl5O8:Tb

426

        Bhushan Dhabekar, E Alagu Raja, T K Gundu Rao*, R K Kher & B C Bhatt

 

 

 

Confirmation studies of correlation between TL and ESR of natural calcium fluoride

429

        M P Chougaonkar* & T K Gundu Rao

 

 

 

Effect of thermal annealing on the thermoluminescence glow curve of  X-irradiated BaSO4:Pr

432

        M Deben Singh, Y Rangeela Devi & S Dorendrajit Singh*  

 

 

 

Thermally stimulated luminescence studies of undoped, Cu and Mn doped BaSO4 compounds

435

        J Manam* & S Das  

 

 

 

Photoluminescence and EPR investigation of combustion synthesized BaAl2O4:Cr3+

439

        Vijay Singh*, Manoj Tiwari, Manish Soni, Mahendra Aynayas, Seok-Hee Hyun, H Y Kwak & V Natarajan  

 

 

 

Combustion synthesis and photoluminescence of Eu2+ doped BaB8O13

441

    R P Sonekar*, S K Omanwar & S V Moharil  

 

 

 

Upconversion luminescence in Eu3+ activated SrAl12O19 nanophosphor

444

        Abhay D Deshmukh, S J Dhoble*‍, Animesh Kumar, D R Peshwe, S V Godbole & M K Bhide  

 

 

 

Effect of Mg and P ions on photoluminescence characteristics of Li2SO4: Cu phosphor

447

        A N Yerpude , S P Puppalwar, S J Dhoble* & Animesh Kumar  

 

 

 

Optically stimulated luminescence dating of artifacts excavated from Kangla, Manipur, India

450

        S Nabadwip Singh*  

 

 

 

Thermoluminescence studies of BaMgAl10O17 doped with Eu phosphors

453

        A P Zambare*, A S Sai Prasad, V Natrajan, B Nageswara Rao & K V R Murthy  

 

 

 

Thermoluminescence characteristics of MgB4O7, MgB4O7:Mn and MgB4O7:Cu phosphors

456

        M Ramalingeswara Rao*, B Subba Rao, N Poornachandra Rao, K Somaiah & K V R Murthy  

 

 

 

Luminescence studies in KMgF3:Eu,Ag

459

        U Madhusoodanan, M T Jose, R Indira & T K Gundu Rao*

 

 

Authors for correspondence are indicated by (*)

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 399-401 

 

 

Development of plasma display panel phosphors at
National Physical Laboratory, New Delhi

R S Yadav, A F Khan, Harish Chander, D Haranath, Ashish Yadav, A K Sharma1 & Santa Chawla*

National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110 012

1Central Electronics Engineering Research Institute, Pilani, Rajasthan 333 031

*E-mail: santa@nplindia.org

Received 24 February 2009; accepted 22 April 2009

Plasma Display Panel (PDP) phosphors of three primary colours red, green and blue (RGB) have been developed for application in 50” HDPDP panel at SAMTEL. Three phosphors one each for red, green and blue was zeroed down. Synthesis processes by high temperature solid state reaction were optimized to achieve maximum quantum efficiency. We have also synthesized RGB nanophosphors by autocombustion method and compared with bulk RGB phosphor. Photoluminescence emission characteristics under VUV (172 nm) and UV (250 nm) excitation of the RGB phosphors show their suitability for PDP applications.

Keywords: Plasma display panel, Phosphors, Nanophosphors, Autocombustion                                                                   

 

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 402-405

 

 

Effect of heating rate on TL glow curves – Theoretical and experimental studies

 

Munish Kumar, G Chourasiya, R K Kher, B C Bhatt* & C M Sunta**

Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085

*CSIR Emeritious Scientist, C/o RP&AD, BARC, ** C30/257 MIG Colony Bandra – East, Mumbai 400 051

E-mail: munish_pms@rediffmail.com

Received 24 February 2009; accepted 30 April 2009

In the absence of thermal quenching but at the same radiation dose, the area under the glow curve at different heating rates is conserved only in TL - time plots and is not conserved in TL-temperature plots. Further at a given heating rate, the glow peak height is same in time as well as in temperature plots and the glow peak height increases with the increase of the heating rate. However to conserve area in TL - temperature plots, the TL intensity when divided by the respective heating rate lead to the decrease of glow peak height in TL/b-temperature plots, which is the artifact of the normalization process. The effect of heating rate on TL glow curves has been investigated theoretically as well as experimentally. The ambiguity prevalent in literature regarding the effect of heating rate on TL glow peak height and area under the glow curves when glow curves are plotted in time or temperature scales has been attempted to resolve. It is suggested that researchers should always present un-normalized as well as normalized TL glow curves if the glow curves (for TL sample exposed to same radiation dose) are recorded at different heating rates.

Keywords: Thermoluminescence glow curves, Heating rate

 

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 406-408

 

 

Trap spectroscopy of microcline in the temperature range 77-600 K

 

K Bishal Singh, A B Ahmed** & R K Gartia*

Department of Physics, Manipur University, Imphal

** Department of Physics Goalpara College, Goalpara

*E-mail: rkgartia@yahoo.co.in

Received 24 February 2009 ; accepted 6 April 2009

Trap spectroscopy of microcline (KAlSi3O8) has been determined by deconvoluting two monochromatic (435 and 285 nm) glow curves. Unlike most studies performed in the range LNT to RT and RT to 400°C separately, in this work thermal scan of the trapping levels has been done right from LNT (77 K) to 600 K. As many as 15 trapping levels could be identified. The most remarkable finding of this analysis is that in microcline, practically all the glow peaks follow second order kinetics, a point that will be discussed critically. For 77K to RT, the frequency factor (s) lies in the range 105 £ s £108 while in the range RT and »300°C, it lies in the range 107£ s £1012. E ~ Tm plot both for UV and blue emission fit to similar equations;

 

Eblue=0.12 exp (0.0045 Tm)                                                  …(1)

EUV=0.11 exp (0.0049 Tm)                                                   …(2)

 

The lifetime (t) of electrons trapped in the trap of depth » 1.5 eV (300°C glow peak) is more than 107 years justifying the use of feldspar in long range dating.

Keywords: Trap spectroscopy, Microcline, Thermoluminescence

   

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 409-412

 

Kinetic parameters of thermoluminescence glow curves of
g-irradiated green calcite

 

T Dwijen Singh & S Dorendrajit Singh*

Department of Physics, Manipur University, Canchipur, Imphal 795 003

*E-mail: dorendrajit @yahoo.co. in

Received 24 February 2009; accepted 30 April 2009

The thermoluminescence (TL) glow curves of green calcite irradiated with different doses (1116, 558, 278, 186 and 93 Gy) of g-rays have been studied. The experimental glow curve shows the presence of three peaks with peak temperatures at 413, 503 and 603K. The activation energy and order of kinetics are determined using the computerized glow curve deconvolution (CGCD). Most of the glow curves obey non-first order kinetics.

Keywords: Computerised glow curve deconvolution, Thermoluminescence, Trapping parameters

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 413-416

 

Effect of temperature of optical stimulation on thermoluminescence
peak of synthetic quartz

 

Y D Kale & Y H Gandhi

Luminescence Research Laboratory, Applied Physics Department, Faculty of Technology and Engineering,
The M S University of Baroda, Vadodara

Received 24 February 2009; accepted 25 March 2009

Several researchers have utilized physical treatments such a annealing temperature, annealing duration, ionizing radiation, grain size and optical bleaching as well as temperature of optical stimulation to establish the definite correlation between TL/OSL sensitivity and colour center with a view to suggest most appropriate physical treatment to be given to the specimen. The effect of temperature of optical stimulation (stimulation at room temperature (RT) (25°C) and stimulation at 160°C) on TL sensitivity, stability of TL peak and role of colour center for specimen annealed at 600°C and 1000°C followed by various beta doses has been studied in the present paper. The TL dose response curves were also plotted for each annealed sample after completion of optical stimulation. The present work reports that the 210°C TL peak is predominant for the specimens annealed at 1000°C prior to optical stimulation at room temperature. This peak remains thermally stable at 210°C and grows with dose systematically regardless of temperature of optical stimulation. The TL peak at 375°C is found to be intense, when the optical stimulation was performed at room temperature or elevated temperature of 160°C. The changes in TL glow curve pattern and sensitivity are strongly attributed to the role of E1center and Ge enter.

Keywords: Optical stimulation, Thermoluminescence, Synthetic quartz

 

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 417-419

 

Analysis of glow curves of quartz and transluminescence dating

 

R K Gartia, L Lovedy & U Ranita

Department of Physics, Manipur University, Imphal 795 003

E-mail: rkgartia@yahoo.co.in

Received 24 February 2009; accepted 22 April 2009

Computerised Glow Curve Deconvolution (CGCD) of glow curves of (N, N+10 and N+15 Gy) sedimentary quartz has been studied. Equivalent dose (ED) of the sample has been evaluated using the well-known additive dose method by using the individual glow peaks obtained by deconvolution. For unheated sediments, ED can be evaluated either using 312°C peak or 276°C peak. The high temperature peaks, located by us around 420, 458, 488 and 540°C normally not considered for dating may also be used in case of heated sediments/potteries/bricks. Unlike the random values of trap-depth reported in some recent paper, our CGCD results clearly show a linear relation between E~kTm plot, yielding a physically realistic Urbach’s co-efficient i.e. 27 for quartz.

Keywords: Glow curve, Transluminescence, Quartz, Computerised glow curve deconvolution

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 420-425

 

Role of defect centres in thermoluminescence mechanism of Tb3+doped MgAl2O4

 

E Alagu Raja, Bhushan Dhabekar, Sanjeev Menon, S P More, T K Gundu Rao* & R K Kher

Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085

*Regional Sophisticated Instrumentation Centre, IIT, Powai, Mumbai 400 076

E-mail : e_alaguraja@yahoo.com

Received 24 February 2009; accepted 20 April 2009

Magnesium aluminate (MgAl2O4) doped with terbium was prepared by combustion synthesis. Defect centres of MgAl2O4:Tb are studied by correlating various techniques such as Electron Spin Resonance (ESR), Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL). TL studies on MgAl2O4:Tb3+ show two TL peaks at 120 and 340°C. MgAl2O4:Tb3+ exhibits OSL when stimulated with 470 nm blue light. ESR study shows two defect centres with g = 2.011 and g = 2.0052 which are assigned to V- centre and F+ centre, respectively. Step annealing ESR technique study suggests that V-centre is correlated to 120°C TL peak whereas F+ centre is correlated with both the 120 and 340°C TL peaks. A TL mechanism is proposed. ESR–OSL correlation studies are carried out. The results of ESR-OSL correlation study along with TL bleaching study support the proposed TL mechanism of 120°C TL peak.

Keywords: Thermoluminescence, MgAl2O4, Defect centres, Electron spin resonance

 

 Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 426-428

 

Thermoluminescence, optically stimulated luminescence and ESR
studies on LiAl5O8:Tb

Bhushan Dhabekar, E Alagu Raja, T K Gundu Rao*, R K Kher & B C Bhatt#

Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085

*R S I C, Indian Institute of Technology, Powai, Mumbai 400 076

#Emeritus Scientist, CSIR

E-mail: gundu@iitb.ac.in; gundu54@yahoo.com

Received 24 February 2009; accepted 30 April 2009

The LiAl5O8:Tb phosphor has been prepared by solution combustion synthesis. LiAl5O8:Tb shows two TL peaks at 160 and 330°C, respectively. Continuous Wave OSL (CW-OSL) of LiAl5O8:Tb phosphor is recorded. ESR studies have been carried out to identify defect centres responsible for TL peaks observed in LiAl5O8:Tb. Room temperature ESR spectra of irradiated LiAl5O8:Tb phosphor exhibit two distinct centres. The first ESR line is assigned to a V-centre. The second ESR line is assigned to F+ centre. Both the ESR lines appear to correlate with the 160°C TL peak of LiAl5O8:Tb phosphor.

Keywords: Thermoluminescence, Optically stimulated luminescence, ESR, Phosphor

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 429-431

 

Confirmation studies of correlation between TL and ESR of
natural calcium fluoride

M P Chougaonkar & T K Gundu Rao@

Radiation Physics & Advisory Division, BARC, Trombay, Mumbai 400 085

@ RSIC, Indian Institute of Technology, Mumbai 400 076

E-mail: mpckar@hotmail.com

Received 24 February 2009; accepted 30 April 2009

Thermoluminescence (TL) and electron spin resonance (ESR) studies were carried out on natural calcium fluoride (Chougaonkar M P & Gundu Rao T K, Proc NCLA-2005, 2005). It was speculated from the studies that the first two TL peaks appearing approximately at 115 and 200oC may be related to two distinct O2-(I) and O2-(II) radicals, respectively. To assess the validity of the correlation between two ESR centres and the TL peaks, CaF2 without oxygen impurities were obtained by growing single crystals of natural CaF2 in oxygen free atmosphere. The oxygen contents in the host material were also removed using PbF2 as scavenger during the growth. ESR spectrum and TL glow curves were then recorded to study the effect of removal of oxygen from the lattice. The studies indicate that the addition of PbF2 leads to the removal of precursors of O2- radicals as well as CaO present in the lattice and yields clear transparent crystals. It has also been observed that the glow peaks appearing at 115 and 200oC were drastically reduced indicating the near absence of centres responsible for the TL peaks. ESR studies shows the absence radicals O2- I as well as O2- II, thus confirming that these centres are responsible for the TL peaks.

Keywords: Thermoluminescence, Electron spin resonance, Calcium fluoride

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 432-434

 

Effect of thermal annealing on the thermoluminescence glow curve of
X-irradiated BaSO4:Pr

 

M Deben Singh, Y Rangeela Devi & S Dorendrajit Singh

Department of Physics, Manipur University, Canchipur, Imphal 795 003

Received 24 February 2009; accepted 30 April 2009

             Barium sulphate doped with Pr (0.27 mol%) has been synthesized by chemical methods. Thermoluminescence (TL) glow curves of BaSO4:Pr sample annealed at different temperatures 620, 670, 720, 770 and 820 K, respectively have been recorded after irradiation with X-rays. The observed TL glow curves show a prominent peak at Tm (=436-440) K and two daughter peaks at temperatures (388-399) and (469-477) K, respectively. The dose response curves of the sample annealed at 770 K for 1 h after Tc=450 K is also recorded. Trapping parameters of observed glow curves can be calculated by conventional techniques.

Keywords:   Glow curve, Thermal annealing, Thermoluminescence

 

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 435-438

 

Thermally stimulated luminescence studies of undoped,
Cu and Mn doped BaSO4 compounds

 

J Manam* & S Das

Department of Applied Physics, Indian School of Mines University, Dhanbad 826 004

*E-mail: jairam_manam@yahoo.co.in

Received 24 February 2009; accepted 30 April 2009

Thermally stimulated luminescence (TSL) of undoped and doped BaSO4 with activators such as Cu and Mn has been investigated. The polycrystalline samples of undoped and doped BaSO4 are prepared by melting method. The formation of BaSO4 compound is confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) studies. Comparison of TL intensity of the most intensive glow peak of Cu doped BaSO4 compound with that of undoped BaSO4 shows that addition of Cu impurity in BaSO4 compound enhances the TL intensity by about 9 times. However, the addition of Mn impurity to undoped BaSO4 increases the TL intensity by about three times when compared with that of undoped BaSO4. Among the studied samples namely undoped, Cu and Mn doped BaSO4; Cu-doped BaSO4 has been found to be the most sensitive.

Keywords: Thermally stimulated luminescence, XRD, FTIR

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 439-440

 

Photoluminescence and EPR investigation of combustion synthesized BaAl2O4:Cr3+

Vijay Singh a*, Manoj Tiwarib, Manish Sonic, Mahendra Aynayasc, Seok-Hee Hyund , H Y Kwaka & V Natarajane

aDepartment of Physics, Bhoj College, Kotra, Bhopal 462 003, India.

bDepartment of Physics, Manoharbhai Patel Institute of Engineering & Technology, Kudwa Village, Gondia 441 614

cDepartment of Physics, Sadhu Vaswani College, Bairagarh, Bhopal 462 030

dCentre for Scientific Instruments, Kyungpook National University, Daegu 702701, Korea.

eRadiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085

*Email: vijayjiin2006@yahoo.com

Received 24 February 2009; accepted 13 April 2009

Recently, many aluminate materials have been extensively studied as phosphors for the next generation of display and lighting devices. Synthesis of aluminate oxide phosphors has been achieved by a variety of routes: solid-state reactions, sol–gel techniques, microwave processing, hydrothermal synthesis and combustion synthesis. In the present investigation, we have successfully employed low temperature combustion method for the preparation of BaAl2O4:Cr3+. Powder X-ray diffraction analysis was used to characterize the as-prepared combustion products, while the optical properties were studied using photoluminescence. The morphological aspect of the resulting powders was examined by scanning electronic microscopy, which showed crystallites with irregular morphology in the form of plates. PL excitation spectrum revealed two broad intense bands located at 421 nm and 552 nm due to Cr3+ ions, while emission spectrum showed peaks due to Cr3+ ions at 705 nm. EPR spectrum of undoped BaAl2O4 showed signals attributable to unintentional Fe3+ impurity ions, while EPR spectrum of BaAl2O4:Cr3+ contained an additional signal around 3450 G. corresponding to g @ 1.98, typical of Cr3+ions.

Keywords: Photoluminescence, EPR, BaAl2O4:Cr3+, Powder X-ray diffraction

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 441-443

 

Combustion synthesis and photoluminescence of Eu2+ doped BaB8O13

R P Sonekar1, S K Omanwar2 & S V Moharil3

1Department of Physics, G. S. College, Khamgaon

2Department of Physics, S G B Amravati University, Amravati

3Department of Physics, R S T M Nagpur University, Nagpur

Received 24 February 2009; accepted 9 April 2009

The photoluminescence properties of inorganic borate host material BaB8O13 doped with Eu2+ have been studied. The material BaB8O13:Eu2+ was prepared by a novel technique which is a slight variation of solution combustion synthesis. The synthesis is based on the exothermic reaction between the fuel (urea) and oxidizer (ammonium nitrate). The structure of the prepared sample was confirmed by powder XRD technique and photoluminescence properties were investigated. Under UV excitation (254 nm), BaB8O13: Eu2+ shows intense broad emission band peak at 408 nm. The effect of concentration of Eu2+ ions on the PL intensity has also been investigated. It has been observed that the powder sample exhibits highest PL emission intensity for Eu2+ concentration of about 0.03 moles.

Keywords: Combustion synthesis, Photoluminescence, BaB8O13

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 444-446

 

Upconversion luminescence in Eu3+ activated SrAl12O19 nanophosphor

 

Abhay D Deshmukhψ*, S J Dhoble‍, Animesh Kumar, D R Peshweψ S V Godbole§ & M K Bhide§

ψDepartment of Metallurgical and Materials Engineering, VNIT, Nagpur 440 011

Kamla Nehru College, Sakkardara Square, Nagpur 440 009

National Environmental Engineering Research Institute Nagpur 440 020

§Spectroscopy Section, Radiochemistry Division, BARC, Mumbai 400 085

E-mail: sjdhoble@rediffmail.com

Received 24 February 2009; accepted 13 April 2009

The synthesis and optical properties of Eu3+ in SrAl12O19 nanophosphor have been studied. All the phosphors were prepared by combustion synthesis and characterized by XRD, EDS, TGA, DTA, particle size analyzer and photoluminescence measurements are carried out. The XRD characterization shows the formation of hexagonal crystalline SrAl12O19 matched with the JCPDS file no. 00-026-0976. SEM and EDS show the formation of nanophosphor and the presence of aluminium, strontium, europium and oxygen. Luminescent characterization shows the emission at 580 nm (yellow) in the visible region by the 858 nm infrared excitation. These results indicate that the Eu doped material is a promising yellow colour fluorescence powder used in colour display or yellow-LED light device using LASER diode as an excitation source.

Keywords: Upconversion, SEM, TGA, Luminescence, Nanophosphor

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 447-449

 

Effect of Mg and P ions on photoluminescence characteristics of
Li2SO4: Cu phosphor

A N Yerpude, S P Puppalwar, S J Dhoble & Animesh Kumara

Kamla Nehru College, Sakkardara Square,

Nagpur 440 009

 

 

aNational Environmental Engineering and Research Institute, Nagpur

E-mail: sjdhoble@rediffmail.com

Received 24 February 2009; accepted 30 April 2009

Synthesis of the Li2SO4: Cu phosphor has been done by using wet chemical method The XRD technique shows the crystalline nature of the prepared material. Photoluminescence (PL) emission spectra of Li2SO4: Cu phosphor shows the strong prominent peak at 387nm in the violet region of the visible spectrum due to the transition of 3d10↔3d94s1 of Cu+ ion. The increase in photoluminescence of Li2SO4:Cu by co-doping with Mg and P has been studied.

Keywords: Li2SO4:Cu phosphor, Synthesis, Phosphors, Photoluminescence

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 450-452

 

Optically stimulated luminescence dating of artifacts excavated
from Kangla, Manipur, India

S Nabadwip Singh

Luminescence Dating Laboratory, Manipur University, Imphal 795 003

E-mail: nabadwipsingh@yahoo.com

Received 24 February 2009; accepted 30 April 2009

Kangla, located at the heart of Imphal city, is almost intersected by 24°N latitude, 94°E longitude, 2619 feet above the mean sea level. An excavation in 2006 at the site by the State Archaeology Department has yielded potteries and bricks at different levels-1.09, 0.72 and 1.64 meter. Using coarse grain of quartz excavated from these artifacts, three samples have been dated using Single Aliquot Regenerative dose (SAR) protocol. A standard commercial Riso (Denmark) TL/OSL reader (model TL DA-15A) has been used for data acquisition. The optically stimulated luminescence (OSL) ages of the samples are in the range 1450-1500 A.D.

Keywords: Kangla, Dating, Single aliquot regenerative dose protocol, Optically stimulated luminescence

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 453-455

 

Thermoluminescence studies of BaMgAl10O17 doped with Eu phosphors

A P Zambare, A S Sai Prasad**, V Natrajan***, B Nageswara Rao@ & K V R Murthy*

Department of Physics, Agasti Arts, Commerce & D R Science College, Akole, Tal- Akole, Dist- Ahmednagar 422 601

**Physics Department, Vasavi College of Engineering, Hyderabad 500 028

***Radio Chemistry Division, BARC, Mumbai 400 085

@Physics Department, V Government College, Venkatagiri 524 132

*Applied Physics Department, Faculty of Technology & Engineering, M S University, Baroda 390 001

E-mail: avinashzambare2003@yahoo.co.in

Received 24 February 2009; accepted 30 April 2009

BaMgAl10 O17:Eu, phosphors have been synthesized in air atmosphere by high temperature solid state reaction. Two well defined thermoluminescence (TL) glow peaks are shown at 180 and 330°C under gamma irradiation. The TL emission spectra of samples reveal two emission peaks at 617 and 895 nm. These changes are probably due to electronic charges and sizes of Eu3+ dopant ions.

Keywords: Thermoluminescence radiation dosimetry (TLD), Thermoluminescence (TL), Phosphors

 

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 456-458

 

Thermoluminescence characteristics of MgB4O7, MgB4O7:Mn and
MgB4O7:Cu phosphors

 

M Ramalingeswara Rao*, B Subba Rao1, N Poornachandra Rao 1, K Somaiah2 & K V R Murthy

*Department of Physics, Vasavi College of Engineering, Hyderabad 500 028

1Department of Physics, VSR & NVR College, Tenali 522 201, Andhra Pradesh

2Department of Physics, Osmania University, Hyderabad 500 007

Display Materials Laboratory, Applied Physics Department, Faculty of Technology and Engineering
M S University of Baroda, Baroda 390 001

*E-mail muktevirao@yahoo.co.in

Received 24 February 2009; accepted 20 April 2009

The thermoluminescence (TL) characteristics of gamma irradiated MgB4O7, MgB4O7:Mn and MgB4O7:Cu phosphors have been studied in the present paper. These phosphors are tried as candidates for PDP panel phosphors. The method of preparation is a standard solid state reaction method. Thermoluminescence studies of gamma irradiated MgB4O7 show a TL peak at 225°C with TL intensity around 65 units. The introduction of 1% dopants like Mn and Cu changes the TL pattern i.e TL peak temperature shifts towards higher side at 233°C. The introduction of Cu creates a hump around 290°C.

Keywords: Thermoluminescence, Phosphors, Fluorescence

Indian Journal of Pure & Applied Physics

Vol. 47, June 2009, pp. 459-460

 

Luminescence studies in KMgF3:Eu,Ag

U Madhusoodanan, M T Jose, R Indira & T K Gundu Rao*

Radiation Safety Division, IGCAR, Kalpakkam 603 102

*RSIC, Indian Institute of Technology, Powai, Mumbai 400 076

Received 24 February 2009; accepted 30 April 2009

A new sensitive material KMgF3:Eu,Ag has been developed with double dopants europium (Eu) and silver (Ag) by melting equal molecular  proportions of KF and MgF2 along with dopants (0.2 mol % each) in argon atmosphere. Luminescence studies have been carried out in this material to check its possible use in radiation dosimetry applications. Thermoluminescence (TL) studies in this material show that its TL sensitivity is three times that of the existing tissue equivalent material LiF:Mg,Ti (TLD-100), while KMgF3 doped with Eu alone and Ag alone shows sensitivities equal to that of TLD-100. KMgF3:Eu,Ag shows a major TL peak around 240oC unlike TLD-100 which has a complicated glow curve shape. The TL emission spectra of gamma irradiated material show characteristic emission of Eu2+. Compared to KMgF3:Eu, the emission intensity of Eu has been found more in KMgF3:Eu,Ag. Photoluminescence studies show that there is no conversion of Eu2+to Eu3+ on gamma irradiation. Electron spin resonance (ESR) studies have been carried out in this material to check if there is any valance conversion of Eu and Ag. Both the irradiated as well as unirradiated materials show signal for Eu2+ ion and did not show any signal for Ag2+ ion. Hence, in the presence of Ag+ more Eu2+ is entering into the crystal lattice which enhances the luminescence efficiency.

Keywords: Alkali halides, Electron spin resonance, Luminescence, Radiation dosimetry

                                                                                                                             


 


                                                                                                                                                 Foreword

 

 

The discovery of the phenomenon of luminescence dates back to seventeenth century. Since then luminescent materials (phosphors) have played a major role in various light sources, display devices and detection systems. Luminescent materials can convert different types of energy into UV, Visible and IR radiation. Depending upon the form of excitation energy, various luminescence phenomena have been termed as Cathodo-, Photo-, Electro-, Mechano-, Bio-, Lyo-, Sono-, Chemi- and Iono- luminescence. Thermoluminescence is a special case where heating stimulates luminescence in a material that has been previously excited by other form of energy e.g., radiation. Thermally and optically stimulated luminescence find applications in radiation dosimetry and geochronological dating. Luminescent material comprises a host material-insulator or semiconductor doped with an activator usually lanthanide or transition metal atom. Both the host and activator are chosen to achieve luminescence emission suitable for a particular application. Hence, research in luminescent materials involves a number of interdisciplinary fields such as synthesis by various chemical routes, material characterization and study of luminescence excitation by different forms of energy and emission characteristics.

 

Electronic displays such as electroluminescent, vacuum fluorescent, field emission and plasma display panels all use phosphors. This is in addition to the classical applications like fluorescent lamps, CFL, TV tubes and X-ray screens.  Recent thrust in low cost solid state lighting using white LEDs depend heavily on phosphors which are the subject of worldwide research. Discovery of nanophosphors with prospect of highly improved performance in existing devices as well as new applications has added new dimension to the field. Indigenous development of phosphors for plasma display panel TV for application in Indian industry is a laudable effort. Development of new bulk and nanophosphors offers great potential for various applications. Such prospects have made the R & D activities in the field of luminescence very important nationally and internationally at present and will keep up the interest for many years to come. I hope this special issue containing selected papers presented at the “International Conference on Luminescence and its Applications-ICLA- 2008”, held at National Physical Laboratory, New Delhi,  will be useful to researchers in the field.

 

 

 

 

Prof. V S Ramamurthy

Former Secretary, Department of Science & Technology, India

Chairman, Board of Governors, IIT Delhi, Delhi

DAE Homi Bhabha Chair Professor

 

 

 

 

Preface

 

 

A number of research groups in India and abroad are actively engaged in understanding the phenomenon of luminescence in different materials and development of luminescent materials for various applications. The “International Conference on Luminescence and its Applications — ICLA-2008”, was organized jointly by National Physical Laboratory, New Delhi and the Luminescence Society of India (LSI) during February 13-16, 2008 at New Delhi, to bring together researchers in this field and share their achievements. This conference was the third in its series and it received an enthusiastic response. Total 275 abstracts were received and 250 delegates including 60 from countries like US, Canada, Japan, UK, Korea, Belgium, Taiwan and Switzerland have attended the conference. A large spectrum of topics related to luminescence physics and its applications were covered. As luminescence involves a number of interdisciplinary fields like physics, chemistry, material science, geology etc., such an international meeting provided a forum for fusion of interdisciplinary ideas. The scientific sessions covered topics ranging from diamonds and gemstones to geochronology and from biological applications to industrial phosphors and radiation dosimetry.

 

The inaugural address was delivered by Prof. V S Ramamurthy, Chairman, Board of Governors, IIT Delhi, Delhi, who emphasized that luminescence has become a sought after field in present times due to its multifarious applications. Of many important uses, he highlighted the applications of luminescence for displays, lighting and sensors. The contributions to the conference were of high quality and all the oral presentations by Indian and foreign scientists were invited by the organizers. Contributed papers were presented as posters. For the Indian community, it was an excellent occasion to show their research work and interact with international experts. This special issue of the journal is based on the papers presented at the international conference and is being brought out for the benefit of researchers in the field of luminescence. Total nineteen papers based on physics of luminescence and its applications have been selected for this special issue after a stringent process of peer review by technical committee of the conference. Many of the manuscripts were revised and resubmitted based on comments of reviewers. Editors took decision about the acceptance of papers after careful consideration. The special issue will give boost to researchers in the field of luminescence to further contribute with their quality research work. The organizers of the conference and Guest Editors extend their sincere thanks to Mrs Poonam Bhatt and Mrs Prabha Gupta for their genuine efforts and full cooperation in bringing out this special issue on ‘Luminescence and its Applications’.

 

 

                                              Guest Editors

 

 

Dr Vikram Kumar                                             Dr Santa Chawla

Director                                                            Scientist

National Physical Laboratory                             National Physical Laboratory

New Delhi 110 012                                            New Delhi 110 012

 

 

 

 

                                      Author Index  

 

Ahmed A B

406

Aynayas Mahendra

439

Bhatt B C

402, 426

Bhide M K

444

Chander Harish

399

Chawla Santa

399

Chougaonkar M P

429

Chourasiya G

402

Das S

435

Deshmukh Abhay D

444

Devi Y Rangeela

432

Dhabekar Bhushan

420, 426

Dhoble S J

444,447

Gandhi Y H

413

Gartia R K

406, 417

Godbole S V

444

Haranath D

399

Hyun Seok -Hee

439

Indira R

459

Jose MT

459

Kale Y D

413

Khan A F

399

Kher R K

402,420, 426

Kumar Animesh

444, 447

Kumar Munish

402

Kwak H Y

439

Lovedy L

417

Madhusoodanan U

459

Manam J

435

Menon Sanjeev

420

Moharil S V

441

More S P

420

Murthy K V R

453, 456

Natarajan V

439, 453

Omanwar S K

441

Peshwe D R

444

Prasad A S Sai

453

Puppalwar S P

447

Raja E Alagu

426,420

Ranita U

417

Rao B Nageswara

453

Rao B Subba

456

Rao M Ramalingeswara

456

Rao N Poornachandra

456

Rao T K Gundu

420, 426, 429, 459

Sharma A K

399

Singh K Bishal

406

Singh M Deben

432

Singh S Dorendrajit

432,409

Singh S Nabadwip

450

Singh T Dwijen

409

Singh Vijay

439

Somaiah K

456

Sonekar R P

441

Soni Manish

439

Sunta C M

402

Tiwari Manoj

439

Yadav Ashish

399

Yadav R S

399

Yerpude A N

447

Zambare A P

453

   


 

                            Keyword Index   

Alkali halides

459

Autocombustion

399

BaAl2O4:Cr3+

439

BaB8O13

441

Calcium flouride

429

Combustion synthesis

441

Computerised glow curve

deconvolution

406, 417

Dating

450

Defect centres

420

Electron spin resonance

429, 459, 420

EPR

439, 426

Flourescence

456

FTIR

432

Glow curve

417, 432

Heating rate

399

Kangla

450

Li2SO4:Cu phosphor

447

Luminescence

444, 459

MgAl2O4

420

Microline

406

Nanophosphors

399, 444

Optical stimulation

413

Optically stimulated luminescence

426, 450

Phosphors

399, 426,447, 453, 456

Photoluminescence

439, 441, 447

Plasma display panel

399

Powder X-ray diffraction

439

Quartz

417

Radiation dosimetry

459

SEM

444

Single aliquot regenerative dose protocol

450

Synthesis

447

Synthetic quartz

413

TGA

444

Thermal annealing

432

Thermally stimulated luminescence

432

Thermoluminescence glow curves

399

Thermoluminescence radiation

dosimetry

453

Thermoluminescence

406, 417, 413, 420,426, 429, 432,

453,456

Trap spectroscopy

406

Trapping parameters

406

Up-conversion

444

XRD

432