Indian Journal of Pure and Applied Physics


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 ISSN: 0019-5596

CODEN: IJOPAU 44 (3) 205-276

VOLUME  44

NUMBER 3

MARCH 2006

 

CONTENTS






Nuclear Physics

 

Comparative study of the natural radioactivity of some selected rocks from Egypt and germany

209

N K Ahmed, A Abbady, A M El Arabi, R Michel, A H El-Kamel & A G E Abbady*

 

Cross-sections of 14 MeV neutron induced reactions on some isotopes of chromium, zirconium and tin

216

Sneh Lata Goyal* & R K Mohindra

 

Atomic and Molecular Physics

 

Mössbauer, X-ray and magnetization studies of ZnAlxFe2-xO4 system

220

Suman Sharma*& N D Sharma

 

Mechanoluminescence of g-irradiated salt

227

R S Kher*, A K Panigrahi, S J Dhoble & M S K Khokhar

 

Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics and Fluid Dynamics

 

Acoustical investigation of magnesium oxide

230

Kailash, K M Raju* & S K Shrivastava

 

Physics of Gases, Plasmas and Electric Discharges

 

Dispersion and absorption of longitudinal electro-kinetic waves in ion-implanted semiconductor plasmas

235

S Ghosh*, Preeti Thakur & M Salimullah

 

Condensed Matter: Structure, Mechanical and Thermal Properties

 

Growth and characterization of gel grown single crystals of cadmium mercury tetrathiocyanate

243

K Ambujam, K Rajarajan, S Selvakumar, D Prem Anand, Preema C Thomas & P Sagayaraj*

 

Thermodynamic properties of linear rigid tangent chains from Wertheim’s thermodynamic perturbation theory

248

Vivek Kumar Singh & K N Khanna*

 

Studies on size dependent properties of cadmium telluride thin films deposited by using successive ionic layer adsorption and reaction method

254

A U Ubale* & D K Kulkarni

 

Growth and microhardness studies of mixed crystals of (NH4)2SbF5-K2SbF5

260

Elsamma Chacko, J Mary Linet, S Mary Navis Priya, C Vesta, B Milton Boaz &
S Jerome Das*

 

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

 

Dielectric relaxation studies of binary mixture of pyridine and N,N-dimethylformamide in benzene solution using microwaves absorption data

264

Sandeep Kumar*, D R Sharma, N Thakur, N S Negi & V S Rangra

 

Interdisciplinary Physics and Related Areas of Science and Technology

 

Realization of voltage-mode CCII-based allpass filter and its inverse version

269

N A Shah* & M F Rather

 

 

 

__________

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

 

Indian Journal of Pure & Applied Physics

Vol. 44, March 2006, pp. 209-215

   

Comparative study of the natural radioactivity of some selected rocks from Egypt and germany

N K Ahmed, A Abbady, A M El Arabi, R Michel*, A H El-Kamel** & A G E Abbady


Physics Department, Faculty of Science Qena, South Valley University, Egypt
*Institute of the Radiation Protection and Radioecology, Hanover University, Germany
**Physics Department, Faculty of Science, Assiut University, Egypt
Received 14 March 2005; revised 22 November 2005; accepted 4 January 2006

The radioactivity contents of various radionuclides in rocks play an important role in health physics and geo-scientific research. The naturally occurring radionuclides 226Ra, 232Th and 40K are the main sources of radiation in soil and rocks from which traditional building materials are derived. These radionuclides pose exposure risks externally due to their gamma-ray emissions and internally due to radon and its progenies, which emit alpha particles. The activity concentration (Bq/kg) in igneous and metamorphic rock samples from different locations in Egypt and Germany has been analysed. The concentration values of samples for 226Ra, 232Th and 40K were found in the range of 3.9 : 57.4, 3.2 : 53.4 and 202 : 1211 in Egypt and 5.1 : 76, 3.4 : 70 and 10 : 2070, respectively in Germany. Even though these radionuclides are widely distributed, their concentrations depend on the local geological conditions.

Keywords: radioactivity, igneous, metamorphic rock

IPC Code: H01J65/08

 

 

Indian Journal of Pure & Applied Physics
Vol. 44, March 2006, pp. 216-219

 

Cross-sections of 14 MeV neutron induced reactions on some isotopes of chromium, zirconium and tin

Sneh Lata Goyal* & R K Mohindra

*Department of Applied Physics, Guru Jambheshwar University, Hisar 125 001
Department of Physics, Kurukshetra University, Kurukshetra 132 119
Received 30 May 2005; revised 23 November 2005; accepted 6 January 2006

Neutron induced reaction cross-sections of the isotopes 52Cr, 53Cr, 90Zr, 91Zr, 92Zr, 94Zr, 116Sn, 118Sn and 120Sn for (n,p), (n,n’), (n,a) and (n, 2n) reactions have been evaluated at 14 MeV. The computations are based on the evaporation model considering the pre-equilibrium emission mechanism under some approximations. The computer codes ALICE-91, NX-1 and SC2N3N have been used. These cross-sections were also computed using the level density formula of Lang and Le Couteur with and without applying pairing energy correction. The compound nucleus theory based on Fermi gas and evaporation model with optical model potential parameters has been used. The neutron, proton and alpha penetrabilities and inverse reaction cross-sections have been computed using the computer code SCAT-2. The computed cross-sections have been compared with the available experimental values and the results are in fairly good agreement.

Keywords: Neutron induced reactions, Nuclear physics, Neutron energy, Neutron multiplication, Nuclear heating, Nuclear transmutation, Radiation damage

IPC Code: G01T3/00

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, March 2006, pp. 220-226

 

Mössbauer, X-ray and magnetization studies of ZnAlxFe2-xO4 system

Suman Sharma & N D Sharma  

*
Department of Physics, Kurukshetra University, Kurukshetra 136 119
Received 8 July 2005; revised 26 December 2005; accepted 3 January 2006

The structural and magnetic properties of the mixed spinel system ZnAlxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been investigated by X-ray diffraction, SEM, EDAX, magnetization and Mössbauer measurements. The Mössbauer parameters, lattice parameters and crystalline size of the products formed with variation in the composition of Fe and Al ratio are studied. The studies confirm the formation of nano-size ferrite particles. It is observed that the lattice parameters and crystalline size decrease with increasing aluminium concentration. All the samples show super paramagnetic relaxation, except the samples (´=0.8, 1.0) which show super paramagnetic behaviour differentiated on the basis of magnetization. The decrease in area ratio with increase in Al concentration has been explained on the basis of ionic radius. The cationic distribution is calculated on the basis of Mössbauer and magnetization. These observations indicate the existence of a non-collinear structure in a nanoparticles ferrite system. The non-collinear structure in this system is also verified by Neel’s two sublattice model.

Keywords: Mössbauer studies, Magnetization, Normal spinel structure

IPC Code: G01J 3/28

 

 

Indian Journal of Pure & Applied Physics

Vol. 44, March 2006, pp. 227-229

 

Mechanoluminescence of g-irradiated salt

R S Kher, A K Panigrahi*, S J Dhoble** & M S K Khokhar***
Department of Physics, Government Autonomous Science PG College, Bilaspur 495 006
* Government Degree College, Sarangarh 496 445
** Kamla Nehru College, Sakkardara Square, Nagpur 440 009
*** Guru Ghasidas University, Bilaspur 495 009
E-mail: kherrs@rediffmail.com
Received 20 June 2005; revised 23 November 2005; accepted 9 January 2006

The dependence of mechanoluminescence (ML) intensity on g-dose of irradiated salt has been studied. It is found that initially the ML intensity increases with increasing g-dose given to the sample, attains an optimum value around 3×103 Gy then decreases with further increase in g-dose. The spectroscopic study of ML and the effect of optical bleaching and storage (fading) on ML intensity have also been investigated to understand the mechanism of ML excitation in household salt. The radiation-induced changes in food material might also be analyzed by studying their ML properties.

Keywords: Mechanoluminescence, g-irradiation, Colour center

IPC Code: C09K11/00

 

Indian Journal of Pure & Applied Physics

Vol. 44, March 2006, pp. 230-234

 

 

 

Acoustical investigation of magnesium oxide

Kailash, K M Raju# & S K Shrivastava*

Department of Physics, Brahmanand P G College, Rath, Hamirpur 210 431
*Department of Physics, Institute of Basic Sciences, Bundelkhand University, Jhansi 284 128  

#
E-mail: krishnamurtiraju@yahoo.com  
Received 24 May 2005; revised 23 November 2005; accepted 9 January 2006

The higher order elastic constants of MgO starting from basic parameters viz. the nearest neighbour distance, hardness parameter using Coulomb and Börn-Mayer potentials have been obtained. These values are utilized to obtain Grüneisen parameters and non-linearity constants. Non-linearity constants ratio, ultrasonic attenuation due to phonon-phonon interaction (a/f2)p-p and thermo elastic loss (a/f2)th are calculated in a wide temperature range along <100>, <110> and <111> crystallographic directions of propagation for longitudinal and shear waves and compared with available theoretical and experimental results.

Keywords: Elastic constants, Magnesium oxide, Ultrasonics, Semiconducting crystals

IPC Code: B01J 19/10

 

Indian Journal of Pure & Applied Physics  

Vol. 44, March 2006, pp. 235-242

 

   

Dispersion and absorption of longitudinal electro-kinetic waves in ion-implanted semiconductor plasmas

S Ghosh* & Preeti Thakur
School of Studies in Physics, Vikram University, Ujjain 456 010 (M.P.)
and
M Salimullah
Department of Physics, Jahangirnagar University, Dhaka 1342, Bangladesh
Received 4 April 2005, accepted 12 December 2005

Excitation of modified electro-kinetic modes and novel properties introduced due to the presence of negatively charged colloidal particles in otherwise compensated semiconductor plasma are investigated. A compact linear dispersion relation for the electro-kinetic waves in colloids laden semiconductor plasma has been derived by using multi-fluid analysis and Maxwell’s equations. This dispersion relation has been studied for slow and fast electro-kinetic modes. The presence of charged colloids significantly modify the dispersion and absorption characteristics of all possible modes even though colloidal particles, because of their heavy masses do not participate in wave propagation.

Keywords:          Electrostatic waves, Electrostatic oscillations, Plasma effects, Doping, Ion-implantation, Colloids

IPC Code: H01J15/00

Indian Journal of Pure & Applied Physics

 Vol. 44, March 2006, pp. 243-247

 

Growth and characterization of gel grown single crystals of cadmium
mercury tetrathiocynate

K Ambujam, K Rajarajan, S Selvakumar, D Prem Anand,
Preema C Thomas & P Sagayaraj*

*Department of Physics, Queen Mary’s College, Chennai 600 004
Department of Physics, Loyola College, Chennai 600 034
Received 28 February 2005; revised 13 June 2005; accepted 2 January 2006

Relatively large sized colourless transparent crystals of cadmium mercury tetrathiocyanate (CMTC) are grown at near ambient temperature using silica gel in straight test tubes in about one week time. Single crystal XRD studies have confirmed the structure of the grown crystals as tetragonal. The grown crystals are characterized by UV-Vis-NIR and FTIR studies. Kurtz powder technique is employed to confirm their non-linear optic (NLO) behaviour. Thermal analysis proves that CMTC is stable up to 200oC. Microhardness studies reveal that CMTC possesses high Vicker’s hardness value. The dielectric measurement is carried out at room temperature and the variation of ε΄ with frequency has been studied.

Keywords: Crystal growth, Microhardness, Cadmium mercury tetrathiocynate

IPC Code: C30B

 

Indian Journal of Pure & Applied Physics  

Vol. 44, March 2006, pp. 248-253

 

 

Thermodynamic properties of linear rigid tangent chains from
Wertheim’s thermodynamic perturbation theory

Vivek Kumar Singh & K N Khanna

Department of Physics, VSSD College, Kanpur
Received 29 March 2005; revised 23 November 2005; accepted 2 January 2006

     Wertheim’s first order thermodynamic perturbation theory is employed to describe the distinct behaviour of fully flexible and linear rigid chains of varying chain lengths in solid phase. In particular, the solid phases of fully flexible and linear rigid chains of varying chain lengths are compared. Several thermodynamic properties such as fluid-solid co-existence boundaries of linear rigid molecules are greatly displaced towards lower densities with increasing chain length, the higher values of packing fractions for linear rigid chains in comparison to fully flexible chains to achieve the same chemical potential.

Keywords: Flexible and linear rigid chains, Fluid-solid coexistence, Wertheim Perturbation theory

IPC Code:G01K

 

Indian Journal of Pure & Applied Physics  

Vol. 44, March 2006, pp. 254-259

 

   

Studies on size dependent properties of cadmium telluride thin films deposited by using successive ionic layer adsorption and reaction method

A U Ubale1 & D K Kulkarni2
 

1
Department of Physics, Govt. Vidarbha Institute of Science and Humanities, Amravati 444 604
2
Department of Physics, Institute of Science, Nagpur 440 001
Received 26 July 2004; revised 19 January 2005;accepted 10 August 2005

Successive ionic layer adsorption and reaction method (SILAR) have been used to deposit CdTe thin films onto glass substrate using cadmium chloride solution as cationic and sodium tellurite solution as anionic precursor. In order to study size dependent optical, structural and electrical properties, films having different thicknesses from 96 to 312 nm have been prepared by changing SILAR deposition cycles from 50 to 110. The XRD studies show that films were nanocrystalline in nature with Wurtzite (hexagonal) structure. A shift of band gap energy from 1.86 to 1.47 eV, a decrease in electrical resistivity from 10.52 × 101 to 4.78 × 101 Wm (at 528 K), increase in grain size from 14.5 to 32.8 nm and decrease in activation energy from 0.39 to 0.19 eV have been observed when film thickness was varied from 96 to 312 nm.  The films prepared are semiconducting in nature with p-type conductivity.

Keywords : Thin film growth, SILAR,Bandgap energy

IPC Code: H01F 41/30

 

Indian Journal of Pure & Applied Physics  

Vol. 44, March 2006, pp. 260-263

   

Growth and microhardness studies of mixed crystals of (NH4)2SbF5-K2SbF5

  Elsamma Chacko, J Mary Linet, S Mary Navis Priya, C Vesta, B Milton Boaz & S Jerome Das*
Department of Physics, Loyola College, Chennai 600 034

E-mail: jerome@loyolacollege.edu  
Received 8 November 2005; accepted 6 February 2006

Mixed crystals of (NH4)2SbF5-K2SbF5 , an electro-optic material have been grown by isothermal evaporation technique. Powder X-ray diffraction method has been used for structural identification and determination of lattice parameters. Load dependent microhardness measurements on this crystal reveal the mechanical behaviour of the material. The work hardening co-efficient and the yield strength of the material were found to be 11.66 and 2.058 Mpa, respectively.

Keywords: Solution growth, Mixed crystals, Microhardness
IPC Code: B01D9/00

 

Indian Journal of Pure & Applied Physics  

Vol. 44, March 2006, pp. 264-268

 

  Dielectric relaxation studies of binary mixture of pyridine and N,N-dimethylformamide in benzene solution using microwaves absorption data

 

Sandeep Kumar, D R Sharma, N Thakur, N S Negi & V S Rangra

Department of Physics, Himachal Pradesh University, Shimla 171 005
Received 6 July 2005; revised 11 November 2005; accepted 3 January 2006

The dielectric relaxation time (t) of binary mixtures of different molar concentrations of pyridine (C5H5N) and N,N-dimethylformamide (DMF) in benzene solution has been calculated by using standard microwave techniques and Gopala Krishna’s single frequency (9.875 GHz) concentration variational method at different temperatures (25, 30, 35 and 40°C). The solute-solute molecular associations have been proposed. The dielectric relaxation has been found to be an activated process. The energy parameters for this activated process have been calculated and compared with that of viscous flow process.

Keywords: Dielectric relaxation, Binary mixture, Pyridine, N,N-dimethylformamide
IPC Code
: G01R 27/26

 

Indian Journal of Pure & Applied Physics  

Vol. 44, March 2006, pp. 269-271  

  Realization of voltage-mode CCII-based allpass filter and its inverse version

 

N A Shah & M F Rather

Postgraduate Department of Electronics & Instrumentation Technology, 
The University of Kashmir, Srinagar 190 006  
E-mail: farsgr@yahoo.co.in
Received 3 June 2005; accepted 3 January 2006

A voltage-mode (VM) filter implementing first-order allpass (AP) function and its inverse signal is presented. The proposed circuit with one input and one output employs a single CCII, two resistors and one grounded capacitor. The circuit respectively implements allpass (AP) signal and its inverse function by using inverting CCII and non-inverting CCII without requiring change in the circuit topology. The phase angle is adjustable through frequency of the applied signal and/or grounded capacitor without disturbing the realizibility condition. The Personal computer simulation program with integrated circuit emphasis (PSPICE) simulation results are included.

Keywords: Voltage-mode circuits, Allpass filter, Inverse unction, Second generation current conveyor
IPC Code: H01P1/20