Indian Journal of Pure and Applied Physics

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VOLUME 45

NUMBER 6

JUNE 2007

CODEN : IJOPAU 45 (6) 487-558

ISSN : 0019-5596

 

 

 

CONTENTS

 

Nuclear Physics

 

Sensitivity analysis of reflector types and impurities in 10 MW MTR type nuclear research reactor

491

K Khattab* & I Khamis

 

Atomic and Molecular Physics

 

Emission spectra of Eu3+ and Tb3+: Borophosphate oxyfluoride glasses

496

B Sudhakar Reddy & S Buddhudu*

 

FTIR and FT-Raman spectroscopic studies of fired clay artifacts recently excavated in Tamilnadu, India

501

R Palanivel & G Velraj*

 

Condensed Matter: Structure, Mechanical and Thermal Properties

 

Structural study of some d shell liquid metals

509

P B Thakor*, P N Gajjar & A R Jani

 

Microstructural analysis of zirconium triselenide single crystals

514

Kaushik Patel, Rajiv Vaidya & S G Patel*

 

Condensed Matter: Electronic Structure, Electrical, Magnetic, and Optical Properties

 

Effect of doping on stimulated Brillouin scattering in piezoelectric magnetized III-V semiconductors

517

Manjeet Singh* & Praveen Aghamkar

 

Growth, optical and thermal studies of L-arginine perchlorate¾A promising nonlinear optical single crystal

524

S Aruna, A Anuradha , Preema C Thomas, M Gulam Mohamed, S A Rajasekar, M Vimalan,
G Mani & P Sagayaraj*

 

 

 

 

 

Dielectric relaxation of associated ternary liquid mixture from high frequency conductivity measurement of solution

529

S Sahoo, K Dutta, S Acharyya* & S K Sit

 

Effect of g-irradiation on polyvinyl alcohol films doped with some dyes and its use in dosimetric studies

545

N V Bhat, M M Nate, R M Bhat & B C Bhatt*

 

Structural and magnetic properties of zinc ferrite aluminates synthesized by ceramic method

549

Suman* & N D Sharma

 

 

 

___________

*The corresponding author has been indicated by (*) mark in case of papers with more than one author.

 

 


 

 

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 491-495

Sensitivity analysis of reflector types and impurities in 10 MW MTR type nuclear research reactor

K Khattab & I Khamis

Atomic Energy Commission, P O  Box 6091, Damascus, Syria

Received 28 November 2006; accepted 16 April 2007

The 2-D and 3-D neutronics models for 10 MW nuclear research reactor of MTR type have been developed and presented in this paper. Our results agree very well with the results of seven countries mentioned in the IAEA-TECDOC-233. To study the effect of reflector types on the reactor effective multiplication factor, five types of reflectors such as pure beryllium, beryllium, heavy water, carbon and water are selected for this study. The pure beryllium is found to be the most efficient reflector in this group. The effect of the most important impurities, which exist on the beryllium reflector such as iron, silicon and aluminium on the reactor multiplication factor, have been analyzed as well. It is found that the iron impurity affects the reactor multiplication factor the most compared to silicon and aluminium impurities.

Keywords: Nuclear research reactor, Sensitivity, Reflector, Neutronics model, IAEA

IPC Code: G21C

 

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 496-500

 

Emission spectra of Eu3+ and Tb3+: Borophosphate oxyfluoride glasses

 

B Sudhakar Reddy & S Buddhudu*

Department of Physics, Sri Venkateswara University, Tirupati 517 502

*E-mail: profsb_svuniv@hotmail.com

Received 23 January 2007; accepted 20 March 2007

The development and luminescence properties of (0.2 mol %) of Eu3+and Tb3+ ions doped borophosphate oxyfluoride (BPOF) optical glasses have been reported in the following general compositions:

69.8 B2O3-10 P2O5-10 (ZnO/CdO/TeO2)-10 (AlF3/LiF)

Measured emission spectra of Eu3+: BPOF optical glasses have revealed five emissions (5D0 ®7F0,1,2,3&4) at 580, 591, 613, 654 and 701 nm, respectively with lexci = 392 nm (7F0®5L6). In case of Tb3+:BPOF optical glasses, four emissions (5D4®7F6,5,4&3) that are located at 489, 545, 584 and 622 nm have been measured with lexci = 374 nm. For the red (Eu3+) and green (Tb3+) emission bands, decay curves have been recorded to compute their lifetimes. By using relevant energy level diagrams, emission processes in the glasses have been explained.

Keywords: Borophosphate oxyfluoride glasses, Eu3+, Tb3+ ions, Optical analysis, Emission spectra

IPC Code: G01J3/28

 

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 501-508

 

FTIR and FT-Raman spectroscopic studies of fired clay artifacts recently excavated in Tamilnadu, India

R Palanivel & G Velraj*

Department of Physics, Annamalai University, Annamalainagar 608 002

*Department of Physics, Periyar University, Salem 636  011

Received 4 August 2006; revised 20 February 2007; accepted 16 April 2007

The spectroscopic techniques represent one of the most powerful tools to investigate the structure of all the materials and chemical composition of the cultural objects like potteries, tiles and ceramics. The spectroscopic techniques that have been used in the present study are FTIR absorption and Raman scattering spectroscopy. The potteries maintain aesthetic characteristics so that this type of artifacts can be considered very specific trace of every civilization. Therefore, it is of great importance to acquire knowledge about the chemical composition and the manufacturing techniques of an artifact. From the behaviour of the absorption bands and their corresponding Raman shifts in specific regions and their intensity showing the presence of minerals, traces of elements in the clay, the knowledge of the artisans and the conditions of the temperature control to make qualitatively good materials of archaeological artifacts. The temperature of firing and the vitrification stage are also being established in the case of potteries from the recent excavations at Maligaimedu, Thiruverkadu and Palur in Tamilnadu, India.

Keywords: FTIR absorption, Raman shifts, Archaeological Artifacts, Clay minerals

IPC Code: G01J3/28

 

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 509-513

Structural study of some d shell liquid metals

P  B Thakor*, P N Gajjar+ & A R Jani

*Department of Physics, Veer Narmad South Gujarat University, Udhna Magdalla Road, Surat 395 007, Gujarat

+Department of Physics, School of Sciences, Gujarat University, Ahmedabad 380 009, Gujarat

Department of Physics, Sardar Patel University, Vallabh Vidyanagar-388 120, Gujarat

Received 1 March 2006; revised 5 February 2007; accepted 20 April 2007

The Charged Hard Sphere (CHS) reference system is applied to study the structure of some d shell liquid metals viz; Sc, Zr, Pd, La and Pt.  The structure factor S(q), pair distribution function g(r), inter atomic distance r1 and coordination number n1 are calculated using a well established pseudopotential.  The latest local field correction function (S) due to Sarkar et al. (Ref. 18) is applied to introduce the exchange and correlation effects.  It is found that the present results are in good agreement with experimental data.  Thus the CHS reference system alongwith the present model potential is found capable of explaining the structural information of some d shell liquid metals.

Keywords:  Pseudopotential, Structure factor, Pair distribution function, Interatomic distance

IPC Code: C30B

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 514-516

Microstructural analysis of zirconium triselenide single crystals

Kaushik Patel, Rajiv Vaidya & S G Patel

Department of Physics, Sardar Patel University, Vallabh Vidyanagar 388 120, Gujarat

E-mail: shantibhaip@yahoo.com

Received 15 May 2006; accepted 20 March 2007

The zirconium triselenide (ZrSe3) single crystal has been grown by chemical vapour transport technique using iodine as a transporting agent. The optimum condition for the growth of this crystal is given. The stoichiometry of the grown crystals was confirmed on the basis of energy disperse analysis by X-ray (EDAX) and remaining structural characterization was accomplished by X- ray diffraction (XRD) studies. The lattice parameters obtained from the XRD analysis were a= 5.45 Å, b=3.74 Å and c=9.44 Å. This crystal is found to possess monoclinic, layered structure. The X-ray density was found to be 5.63 g/cc and volume was calculated about 193.50 Å3. The optical band gap of the as-grown crystal has been carried out with the help of optical absorption spectra in the range 700 - 1400 nm.

Keywords: ZrSe3 single crystal, EDAX, Optical band gap, Microstructural analysis, Chemical vapour transport, X-ray diffraction, Optical absorption spectra

IPC Code:      C30B

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 517-523

Effect of doping on stimulated Brillouin scattering in piezoelectric
magnetized III-V semiconductors

 

Manjeet Singh & Praveen Aghamkar

Department of Applied Physics, Guru Jambheshwar University of Science & Technology, Hisar 125001

E-mail: msgur_18@yahoo.com

and

P K Sen

Department of Applied Physics, S G S I T S, 23-Park Road, Indore 452 003

Received 15 October 2006; accepted 17 April 2007

Using the hydrodynamic model of a semiconductor-plasma and following the coupled mode approach, an analytical investigation has been made for stimulated Brillouin scattering (SBS) resulting from the nonlinear interaction of an intense pump beam with acoustic perturbations internally generated due to piezoelectric and electrostrictive property of the crystal. The analysis deals with the qualitative behaviour of threshold pump electric field for the onset of SBS and resulting gain coefficient with respect to doping concentration (through plasma frequency) in piezoelectric III-V semiconductors subjected to transverse magnetostatic field. The numerical estimates are made for n-type InSb crystal at 77 K duly shined by pulsed 10.6 μm CO2 laser. The threshold value of pump field required for the onset of SBS is found to lower in the presence of magnetostatic field. At resonance, the Brillouin gain is two hundred and 104 times in the presence of piezoelectricity and magnetostatic field, respectively, than in their absence. Moreover, the SBS gain coefficient increases with increasing in scattering angle and results in maximum value for the backscattered mode. The backward Brillouin gain is found to be 104 times larger than the forward gain. The analysis also suggests the possibility of observing phase conjugation reflectivity as high as ~106 in weakly piezoelectric doped III-V semiconductors subjected to a magnetic field.

Keywords: Stimulated Brillouin scattering, Doping, Piezoelectricity, Magnetic field, III-V semiconductors

IPC Code: G02F1/35

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 524-528

Growth, optical and thermal studies of L-arginine perchlorate—A promising
non-linear optical single crystal

S Arunaa, A Anuradhab, Preema C Thomas, M Gulam Mohamedc, S A Rajasekard, M Vimalan, G Mani & P Sagayaraj

Department of Physics, Loyola College, Chennai 600 034

aDepartment of Physics, Bharathi Women’s College, North Chennai, Chennai 600 108

bDepartment of Electronic Science and Communication, SRM Arts and Science College, Kattankulathur

cDepartment of Physics, The New College, Chennai 600 014

dDepartment of Physics, Vellore Institute of Technology, Vellore 632 014

Received 11 July 2006; revised 5 December 2006; accepted 7 February 2007

Optically good quality single crystal of L-arginine perchlorate (abbreviated as LARPCL), a promising analog of LAP was successfully grown by slow solvent evaporation technique at room temperature. The grown crystals were characterized by single crystal XRD, FTIR, FT-Raman, optical absorption and SEM studies. The thermal stability of the crystal was studied by TG, DTA and DSC analysis. The scanning electron microscopy (SEM) provides information about the surface morphology of the sample. The SHG efficiency is estimated using Kurtz powder method.

Keywords:     Characterization, Growth from solution, X-ray diffraction, Non-linear optical crystal, Thermal analysis,
          L-arginine perchlorate

IPC Code: C30B

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 529-544

Dielectric relaxation of associated ternary liquid mixture from
high frequency conductivity measurement of solution

 

S Sahoo*, K Dutta, S Acharyya & S K Sit

Department of Physics, Dr Meghnad Saha Institute of Technology, P O: Debhog, Haldia

Dist: Purba Medinipur 721 657, West Bengal

E-mail: swapansit@yahoo.co.in

Received 2 August 2006; revised 25 January 2007; accepted 19 April 2007

Dielectric relaxations of two binary (jk) polar mixtures like N-methyl acetamide (NMA) and acetone (Ac) as well as dimethyl sulphoxide (DMSO) and acetone(Ac) dissolved in non-polar solvents (i) benzene and carbontetrachloride were studied at 25, 30, 35, 40 and 25°C temperatures, respectively for 0.0,0.3, 0.5, 0.7, and 1.0 mole fractions xj of acetone under 9.88 GHz and 9.174 GHz electric field from complex high frequency conductivity sijk* =(sijk¢ + jsijk² ) measurement of the ternary solution. The relaxation times tjk’s of the binary polar mixtures were estimated from the ratio of slopes of sijk²- wjk and sijk¢ - wjk curves at wjk®0 as well as the slopes of sijk²- sijk¢ linear equations of existing method [Murthy et al., Indian J Phys, 63B (1989) 491]. They are compared with the reported t ‘s due to Gopalakrishna's method to indicate the validity of both the methods. The proposed method of ratio of slopes seems to be a better choice in which the polar - polar interactions are almost eliminated. The dipole moments mjk 's for both the methods were calculated in terms of slopes b's of sijk - wjk curves at wjk®0 and dimensionless parameters b's and compared with the reported m's. The variations of tjk‘s and mjk‘s with xj of acetone for (NMA+Ac) and (DMSO+Ac) mixture at an experimental temperature are explained on the basis of solute-solvent (monomer) and solute - solute (dimer) associations like mjk -T curve of (NMA+Ac) mixture. The theoretical dipole moments mtheo's were measured from the available bond angles and bond moments of polar groups of the molecules. A little disagreement between measured mjk 's and reported m 's may be due to inductive, mesomeric and electromeric effects of the polar groups of the molecules at different temperatures under high frequency electric field .The thermodynamic energy parameters like enthalpy of activation DHt, entropy of activation DSt and free energy of activation DFt of (NMA+Ac) mixture were estimated from slopes and intercepts of ln (tjkT) against 1/T curves for different xj of acetone from Eyring's rate theory to know the molecular dynamics of the systems.

Keywords: Relaxation time, hf conductivity, Dipole moment, Solute-solute interaction

IPC Code: G01R27/26

 

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 545-548

 

Effect of g-irradiation on polyvinyl alcohol films doped with some dyes and
their use in dosimetric studies

 

N V Bhat1, M M Nate1, R M Bhat2 & B C Bhatt*

1The Bombay Textile Research Association, L. B. S. Marg, Ghatkopar (W), Mumbai 400 086

2Chemical Dosimetry, Radiation Standards Section, Bhabha Atomic Research Centre, Mumbai 400 085

Received 15 May 2006; revised 18 October 2006; accepted 18 April 2007

Using polyvinyl alcohol (PVA), water-soluble polymer, thin films were prepared by incorporating some dyes. On subjecting these films to g-radiation, it was found that there is a gradual change in the colour. In case of PVA film containing methyl red sudden discolouration occurs at a dose of 30 kGy, however, optical density change was not very contrasting. In case of acid red-4, there is a gradual fading of the red colour in the dose range 10-55 kGy. The PVA film (control) without dye shows development of brownish shade. These changes can be explained in terms of scission of main chain, liberation of the H and OH radicals and their interactions with the dye molecules. It is shown that these films can be used as cheap, portable and reliable plastic detectors for dosimetry.

Keywords: Irradiation, Dyes, Plastic, Polyvinyl alcohol, Dosimeter

IPC Code: G01T

Indian Journal of Pure & Applied Physics

Vol. 45, June 2007, pp. 549-554

Structural and magnetic properties of zinc ferrite aluminates synthesized by ceramic method

Suman* & N D Sharma**

*Department of Physics, Kurukshetra University, Kurukshetra 136119

**Department of Electronics and Communication Engineering,
J M Institute of Enginering and Technology, Radaur 135 133

                                      Received 27 June 2006; revised 29 December 2006; accepted 10 January 2007

Mössbauer spectroscopy has been used to investigate the cation distribution in ZnAlxFe2-xO4 spinel ferrites with the composition 0£x£1. All samples were prepared using the ceramic technique. A single phase formation of the compounds did not occur. It is confirmed by X-ray diffraction measurements. The variation in saturation magnetization of the samples at room temperature has been explained on the basis of site distributions and the strength of the exchange interactions between magnetic ions.

Keywords: Structural properties, Magnetization, Mössbauer spectroscopy, Zinc ferrite aluminates, Ceramic technique

IPC Code: G01J 3/12