Indian Journal of Pure and Applied Physics

Total visitors:1,700 since 28-11-05

 

 ISSN: 0019-5596

CODEN: IJOPAU 43 (10) 811-894

VOLUME  43

NUMBER 11

NOVEMBER 2005

CONTENTS

 

Nuclear Physics

 

Evaluation of natural radioactivity and radiological hazards caused by different marbles of India

V Ramasamy*, V Ponnusamy, J Hemalatha, V Meenakshisundaram & V Gajendiran

815

Atomic and Molecular Physics

 

Vibrational spectroscopic characterization of form II poly (vinylidene fluoride)

821

P Nallasamy* & S Mohan

 

Infrared spectroscopic study of zinc doped iron borate glasses

828

Roshan Lal* & N D Sharma

 

ESR, IR and optical absorption studies of Cu2+ spin probe in xNa2O-(50-x)ZnO-50B2O3 ternary glasses

833

J Chinna Babu, S Suresh & V Chandra Mouli*

 

Vibrational spectra and normal coordinate analysis on an organic non-linear optical crystal-3-methoxy-4-hydroxy benzaldehyde

838

S Gunasekaran & S Ponnusamy*

 

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

 

Ultrasonic velocity measurements of binary mixtures of acetone and dioxane with dimethylsulphoxide as one component

844

V K Syal*, S Chauhan & Uma Kumari

 

Ultrasonic studies on the molecular interaction of 1-chlorobenzotriazole with aromatic compounds in solution

849

V Kannappan* & G Hemalatha

 

Surface plasmon resonance based refractive index sensor for liquids

854

Navina Mehan*, Vinay Gupta, K Sreenivas & Abhai Mansingh

 

Condensed Matter: Structure, Mechanical and Thermal Properties

 

Effect of thiourea on the crystal structure of ammonium dihydrogen phosphate

859

A Jayarama & S M Dharmaprakash*

               

Growth and characterization of pure and aniline doped benzoyl glycine single crystals

863

D Prem Anand, S Selvakumar, K Ambujam, K Rajarajan, M Gulam Mohammed & P Sagayaraj*

 

Effect of M2+-cation (M2+ = Zn and Cd) on perovskite synthesis and structural parameters of
Ba(M1/3 Nb1/3Ta1/3)O3 ceramics

869

M Chickpatil & R L Raibagkar*

 

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

 

Charge imbalance generated by tunnel injection in superconductors

873

B A Mattoo* & M A Malik

 

Dielectric studies of polycrystalline (Sr,Fe)TiO3 ceramics

884

K K P Srivastava* & K K Sinha

 

________

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

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 815-820

 

 

Evaluation of natural radioactivity and radiological hazards caused by different marbles of India

V Ramasamya, V Ponnusamya, J Hemalathaa, V Meenakshisundaramb & V Gajendiranb

a Department of Physics, Annamalai University, Annamalainagar 608 002

b Health and Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102

*E-mail: srsaranram@rediffmail.com

Received 25 January 2005; revised 2 August 2005; accepted 12 September 2005

The samples used in this study are of various coloured varieties of marbles collected from marble dealers. The specific activity concentration of  238U, 232Th and 40K has been determined by gamma ray spectrometry. The materials showed concentrations of  238U, 232Th and 40K which were found to be dramatically variable depending on mineral content and type of formation. Using FTIR and thin section analyses, quartz, feldspar, calcite and mafic minerals present in the samples have been determined quantitatively. From our experimental data, it can be seen that the geochemical parameters such as SiO2 or mafic minerals or CaCO3 may be considered to be an appropriate index to select the marbles of low radiological risk. The average specific activities of 40K are found to be higher than 232Th and 238U. The ratio of Th/U was calculated and correlated. Assessment of radiological hazards was made by calculating radium equivalent activities, external and internal hazard indices which were found to vary from 30.92 to 54.45, 0.08 to 0.14 and 0.10 to 0.17 Bq/kg, respectively. The observed values are lower than the recommended limits.

Keywords: Natural radioactivity, Marble, Radiological hazards, Gamma ray spectrometry

IPC Code:G01T

 

 

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 821-827

 

 

Vibrational spectroscopic characterization of form II poly(vinylidene fluoride)

P Nallasamy

Department of Physics, Bharathidasan Govt. College for Women, Pondicherry 605 003

and

S Mohan

Raman School of Physics, Pondicherry University, Pondicherry 605 014

Received 28 December 2004; revised 20 June 2005; accepted 8 September 2005

The Fourier transform Raman (FT-Raman) and infrared absorption (FTIR) spectra of form II poly(vinylidene fluoride) have been recorded and analysed. A complete spectral analysis, assignments to observed bands, normal coordinate analysis and discussion of the spectra are presented. The computed spectrum is in excellent agreement with experiment. The potential energy distribution (PED) is evaluated from respective potential constants to analyse the purity of the modes.

Keywords: Infrared and Raman spectra; Normal coordinate analysis, Poly(vinylidene fluoride), Vibrational spectroscopy

IPC Code: G01J3/00

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 828-832

 

 

Infrared spectroscopic study of zinc doped iron borate glasses

Roshan Lal* & N D Sharma

Department of Physics, Kurukshetra University, Kurukshetra 136 119

Received 27 January 2005; revised 10 September 2005; accepted 15 September 2005

The infrared absorption spectra of xZnO(40-x)Fe2O3.60B2O3 glasses (x = 0, 10, 15, 20 and 30 mol% of ZnO) have been investigated to find out the role played by zinc on the structure of these glasses. ZnO was gradually introduced to replace Fe2O3 in the series of zinc doped iron borate glasses containing 60% B2O3. The structural changes were inferred by monitoring the infrared spectra of these glasses in the range 200-4000 cm-1 by KBr technique. Very small change in absorption bands may occur on addition of ZnO impurity in the series of zinc doped iron borate glasses. No boroxyl ring formation is observed in the structure of these glasses. Similarly, tetrahedral formation of zinc is not observed. The absence of absorption band corresponding to a frequency of 806 cm-1 is attributed to the progressive substitution of boroxol ring by triborate (BO3) and tetraborate (BO4) groups.

Keywords: Infrared spectroscopy, Iron borate glasses, Glasses

IPC Code: G01J3/42

 

 

Indian Journal of Pure and Applied Physics

Vol. 43, November 2005, pp. 833-837

 

ESR, IR and optical absorption studies of Cu2+ spin probe in
xNa2O-(50-x)ZnO-50B2O3 ternary glasses

 

J Chinna Babu, S Suresh & V Chandra Mouli

Glassy Materials Research Laboratory, Department of Physics, Osmania University, Hyderabad 500 007, Andhra Pradesh

< vorucm90@yahoo.com >

Received 28 February 2005; revised 20 July 2005; accepted 16 September 2005

ESR, IR and optical absorption studies on xNa2O-(50-x)ZnO-50B2O3 ternary glasses containing Cu2+ spin probe have been carried out. The absence of band at 806 cm-1 in the IR spectra indicates the absence of boroxol rings. Thus, the present glass system consists of borate triangles [BO3] and borate tetrahedral [BO4] structural units. It was also observed that structural changes are taking place with variation of Na2O and ZnO contents. The hyperfine splittings in the parallel features of ESR spectra of Cu2+ are recorded for all compositions. ESR results show that the g|| > g^ indicating that the Cu2+ ion is in tetragonal distorted octahedral site and its ground state is dx2-y2. There is considerable variation in g|| and A|| values with the increasing concentration of Na2O, whereas no perceptible changes have been observed in g^ and A^ values. The observed optical absorption peak of Cu2+ has been found to be at 800 nm for x=25 mol% of Na2O content. Bonding parameters are calculated from both optical and ESR data. All these variations clearly indicate the structural changes in the present glass system with varying Na2O content.

Keywords: ESR absorption, IR absorption, Optical absorption, Glasses, Cu2+ spin probe

IPC code: G01J3/42

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 838-843

 

 

Vibrational spectra and normal coordinate analysis on an organic non-linear optical crystal-3-methoxy-4-hydroxy benzaldehyde

 

S Gunasekaran1 & S Ponnusamy2

1Postgraduate and Research Department of Physics, Pachaiyappa’s College, Chennai 600 030

2Department of Physics, S R M Institute of Science and Technology, Kattankulathur 603 203

Received 13 April 2005; revised 19 August 2005; accepted 2 September 2005

The crystal 3-methoxy-4-hydroxy benzaldehyde (vanillin) is a potential non-linear organic crystal. The FTIR and laser Raman spectroscopy have been used to make a qualitative analysis and structural confirmation on vanillin. The molecular structure of vanillin belongs to Cs point group symmetry. A normal coordinate analysis of vanillin has been carried out following Wilson’s F-G matrix method using the general quadratic valence force field. A set of orthonormalised symmetry coordinates satisfying the transformation properties is constructed. The validity of the vibrational assignments is supported evaluating the potential constants of the molecule of vanillin. Further, the potential energy distribution has also been evaluated to check, whether the chosen set of vibrational frequencies contribute to the maximum potential energy associated with the normal coordinate of the molecule.

Keywords: Normal coordinate analysis, FTIR, Laser Raman spectra, Non-linear optical, Vanillin, F-G matrix

IPC Code: G01J3/44

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 844-848

 

 

 

Ultrasonic velocity of binary mixtures of acetone and dioxane with dimethylsulphoxide as one component

 

V K Syal, S Chauhan & Uma Kumari

Chemistry Department, Himachal Pradesh University, Shimla 171 005

Received 20 September 2004; revised 13 April 2005; accepted 16 August 2005

Ultrasonic velocities, densities and viscosities of pure dimethylsulphoxide (DMSO), acetone (Ac) and DMSO + Ac mixture have been measured for different compositions at 25, 35 and 45°C at 1 MHz and for DMSO + dioxane solvent systems at 25°C at 2 MHz.Various excess functions e.g. excess adiabatic compressibility (bE), excess volume (VE), excess viscosity (hE) etc. have also been evaluated from the measured data and discussed to substantiate the existence of intermolecular interactions present in liquid mixtures for both the solvent systems.

Keywords: Ultrasonic velocity, Acetone, Dioxane, Dimethylsulphoxide, Viscosiy

IPC Code: B01J19/16

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 849-853

 

 

Ultrasonic studies on the molecular interaction of 1-chlorobenzotriazole with aromatic compounds in solution

 

V Kannappan* & G Hemalatha

Post-Graduate and Research Department of Chemistry, Presidency College, Chennai 600 005.

Received 1 November 2004; revised 19 March 2005; accepted 12 September 2005

The ultrasonic velocities (U) and densities (r) are measured for solutions of biphenyl, thioanisole and diphenylsulphide and mixtures containing equimolar concentrations of these compounds and 1-chlorobenzotriazole (1-CBT) at 303 K in the concentration range 6´10-4-3´10-3 M. Toluene was used as solvent for the biphenyl-1-CBT system and
1,4-dioxane was used as solvent for the other two systems. The coefficient of viscosity (
h) values are determined for the mixtures at 303 K. The acoustical parameters such as adiabatic compressibility (b), free length (Lf), relaxation time (t) and free energy of activation (DG#) values are also calculated. The trend in acoustical parameters indicate that there are molecular interactions between the components and the formation of a charge transfer complex between aromatic compound (donor) and 1-CBT (acceptor) is established.

Keywords: Ultrasonic velocity, Molecular interactions, Acoustical parameters, Adiabatic compressibility, Free length, Relaxation time

IPC Code: B01J19/10

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 854-858

Surface plasmon resonance based refractive index sensor for liquids

Navina Mehan, Vinay Gupta, K Sreenivas & Abhai Mansingh

Department of Physics and Astrophysics, University of Delhi, Delhi 110 007

Email:navinamehan@yahoo.com

Received 4 July 2005; accepted 13 September 2005

A surface plasmon resonance (SPR) refractive index sensor for liquids was fabricated and characterized. A thin silver (Ag) film (545Å) was deposited on a prism face and surface plasmon modes were excited along the interfaces of Ag and air, Ag and water and Ag and sugar solutions by prism-coupling using a He-Ne laser. The experimental SPR reflectance curves shifted continuously with increase in sugar concentration. Theoretical fitting of the SPR dip angles yielded the dielectric constant of Ag and refractive indices of water and sugar solutions. A maximum sensitivity of 1.4×10-4 R.I.U. (refractive index units) was achieved with SPR dip angle as variable parameter. With SPR reflectance as variable parameter at a fixed angle, the maximum sensitivity was 3.9×10-5 R.I.U. in a selected narrow range of refractive index.

Keywords: Surface plasmon resonance, Refractive index sensor, Optical characterization, Thin metal films

IPC Code: G01N21/49

 

 

 

 Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 859-862

 

Effect of thiourea on the crystal structure of ammonium dihydrogen phosphate

A Jayarama & S M Dharmaprakash

Department of Physics, Mangalore University, Mangalagangotri 574 199

E-mail: smdharma@yahoo.com

Received 17 May 2005; accepted 22 July 2005

The crystal structure of thiourea mixed ammonium dihydrogen phosphate (ADP) was determined at 116(2) K. Temperature variation of thermal vibrations signifies the existence of a disordered character of atoms. The structure was solved using SHELXS-97 and refined with SHELXL-97. A direct-method solution was calculated which provided positions of non-hydrogen atoms from the E-map. Full-matrix least squares/difference Fourier cycles were performed to locate the hydrogen atoms. All non-hydrogen atoms were refined with anisotropic displacement parameters. The unique hydrogen on the nitrogen and the half-weight hydrogen on the oxygen atom were refined as isotropic contributors in the final cycles of refinement. It follows that the mechanism of the phase transition is dominated by the disorder-like motion of the NH4+  ion rather than the PO4 tetrahedron.

Keywords: Crystal structure, Ammonium dihydrogen phosphate, Non-linear optical, Thiourea, Dielectric, Antiferroelectric

IPC Code: C30B

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 863-868

 

Growth and characterization of pure and aniline doped benzoyl glycine
single crystals

D Prem Anand1, S Selvakumar1, K Ambujam2, K Rajarajan1,

M Gulam Mohammed3 & P Sagayaraj1

1Department of Physics, Loyola College, Chennai 600 034

2Department of Physics, Queen Mary’s College, Chennai 600 004

3Department of Physics, The New College, Chennai 600 014

Received 9 March 2005; accepted 14 September 2005

Optically good quality single crystals of organic non-linear optical pure benzoyl glycine (BG) and aniline doped BG of dimensions up to 5´4.5´5 mm3 and 3x3.5´2.5 mm3, respectively, are grown by solution growth technique. The grown crystals are characterized by single crystal XRD, FTIR, optical absorption, thermogravimetric(TG) analysis, microhardness, dielectric and photoconductivity studies. The microhardness studies suggest that the aniline substituted crystals have improved Vickers hardness number (VHN) values than the pure ones. The Non-linear Optical (NLO) test confirms the second harmonic signal generation in both pure and doped samples. The thermal studies of the pure and doped BG crystal indicate a marginal increase in the thermal stability of the doped crystal. The dielectric response of the sample is studied in the frequency region of 50 Hz - 500 kHz and the influence of aniline substitution on the dielectric behaviour has been investigated. Photoconductivity studies of pure and doped BG crystal reveal the positive photoconducting nature.

Keywords: Solution growth, Organic NLO, Benzoyl glycine (BG), FTIR, Dielectric, VHN, Microhardness

IPC Code: C30B

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 869-872

 

 

Effect of M2+-cation (M2+=Zn and Cd) on perovskite synthesis and
structural parameters of Ba (M1/3 Nb1/3Ta1/3)O3 ceramics

M Chickpatil* & R L Raibagkar†

*Department of Applied Electronics, Gulbarga University, Gulbarga 585 106, Karnataka

Department of Materials Science, Gulbarga University, Gulbarga 585 106, Karnataka

E-Mail: chickpatil@rediffmail.com & rlraibagkar@rediffmail.com

Received 29 March 2005; revised 7 July 2005; accepted 16 August 2005

Polycrystalline samples of Ba(Zn1/3Nb1/3Ta1/3)O3 and Ba(Cd1/3Nb1/3Ta1/3)O3 have been prepared by solid state reaction technique. Preliminary X-ray studies showed the formation of single-phase compound. Zinc doped barium niobium tantalet had a cubic unit cell and cadmium doped barium niobium tantalet had a tetragonal structure. The d-values and intensities for each reflection were computed using the lattice parameters, which agree well with the observed values. The calculated and order line intensities for both compounds decreased in the ordered which is expected from the differences in the atomic scattering factor of B-ions, thus confirms the 1:1 degree of cation ordering.

Keywords: M2+-cation, Perovskite synthesis, Structural parameters, Polycrystalline ceramics

IPC Code: C04B33/00

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 873-883

 

 

Charge imbalance generated by tunnel injection in superconductors

*B A Mattoo & M A Malik

Department of Physics, S P College, Srinagar 190 001, Kashmir

*Email: bamattoo@yahoo.com

Received 29 June 2004; revised 29 November 2004; accepted 13 January 2005

Using quasi– classical Green function, charge imbalance relaxation rates in tunnel injection experiments are calculated. It yields accurate results even when pair-breaking rate is comparable with the gap frequency.

Keywords: Tunnel injection, Charge imbalance, Green function

IPC Code: H01L39/00

 

Indian Journal of Pure & Applied Physics

Vol. 43, November 2005, pp. 884-888

 

Dielectric studies of polycrystalline (Sr,Fe)TiO3 ceramics

 

K K P Srivastava & K K Sinha

Department of Physics, T M Bhagalpur University, Bhagalpur 812 007

Received 24 December 2004; accepted 30 August 2005

The characteristic properties of polycrystalline (Sr,Fe)TiO3 ceramics have been studied through Mössbauer, EPR, IR and differential scanning calorimetry because perovskite type dielectrics have useful applications in electronic industry. In Fe-doped materials, the small concentration of Fe atoms provides active centres that can be probed through Mössbauer and EPR methods which are precise enough to detect small lattice structural perturbations and yield valuable information. The present work deals with their dielectric properties including dielectric relaxation time that is considered an important study from a theoretical angle. It is found that the two-state Debye relaxation model is inadequate. These ceramics tend to behave like relaxors with ferroelectric transition temperature in the range 200-250°C depending upon iron concentration.

Keywords: Ferroelectric ceramics, Relaxor, Dielectric relaxation

IPC Code: G01N33/38