Indian Journal of Pure and Applied Physics

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Volume 45                                                        Number 7                                JULY 2007

CODEN : IJOPAU 45 (7) 559-632                                                                   ISSN : 0019-5596

     

CONTENTS

 

Atomic and Molecular Physics

 

FTIR analysis of high energy heavy ion irradiated kapton-H polyimide

563

Maneesha Garg & J K Quamara*

 

High resolution electronic absorption spectrum of 1,3,5-trifluorobenzene

569

R P Tiwari, S N Thakur & R A Singh*

 

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

 

Acoustical behaviour of glycerine, dextrose and sucrose in Na2CO3 and NaHCO3 buffer solution

573

A N Kannappan* & R Palani

 

Study of molecular interactions in binary mixtures of benzene-butanol and toluene-butanol systems from acoustic and thermodynamic parameters

580

Rita Mehra* & Meenakshi Pancholi

 

Condensed Matter: Structure, Mechanical and Thermal Properties

 

Growth and thermal studies of nonlinear optical L-argininium diiodate L-argininium dinitrate and
L-argininium hydrochloride bromide single crystals

591

Preema C Thomas, S Aruna, J Madhavan, Reena Ittyachan, Joseph Arul Pragasam,
Joe G M Jesudurai, K Prabha & P Sagayaraj*

 

Effect of nickel substitution on structural, infrared and elastic properties of lithium ferrite

596

S S Bhatu, V K Lakhani, A R Tanna, N H Vasoya, J U Buch, P U Sharma, U N Trivedi,
H H Joshi & K B Modi*

 

 

 

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

 

Temperature dependence of dielectric properties of sodium potassium niobate ceramics

609

S C Bhatt, K Singh, M Uniyal, Om Prakash, Pankaj K Singh, R Saxena  & B S Semwal*

 

Solar selective properties of copper-aluminium composite films

613

T S Sathiaraj

 

Electrical and optical studies of corona poled 4-hydroxy-4¢ -nitroazobenzene doped polymethylmethacrylate films

618

Niraj Kalra, D K Chaturvedi, Sushil Kumar & Sanjiv Arora*

 

Photoelectric properties of CdS thin film prepared by chemical bath deposition

624

R Devi, P Purkayastha, P K Kalita, R Sarma, H L Das & B K Sarma*

 

 

___________

*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, July 2007, pp 563-568

FTIR analysis of high energy heavy ion irradiated kapton-H polyimide

Maneesha Garg & J K Quamara*

Department of Applied Physics, National Institute of Technology, Kurukshetra 136 119

*E-mail: jkquamara@yahoo.com

Received 28 November 2006; accepted 1 May 2007

FTIR spectroscopy technique has been applied for the analysis of high energy heavy ion irradiated kapton-H polyimide. The kapton-H samples were irradiated with 75 MeV oxygen, 80 MeV nickel and 50 MeV lithium ions at PELLETRON facility, Nuclear Science Centre, New Delhi . A very broad peak in 2500-3500 cm-1 is due to the presence of absorbed water in irradiated samples. The reduction in the intensity of 1702 cm-1 peak in irradiated samples as compared to pristine samples is associated to the demerization of carbonyl groups. The increase in the intensity of this peak with increase in fluence is due to the increase in cross-linked structure causing the reduction in demerization of carbonyl groups. The FTIR spectrum is independent of the nature of ion.

Keywords: High energy heavy ion irradiation, Kapton-H polyimide, FTIR spectroscopy

IPC Code: G01J3/28

 

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 569-572

 

High resolution electronic absorption spectrum of 1, 3, 5-trifluorobenzene

R P Tiwari, S N Thakur & R A Singh*

Department of Physics, Banaras Hindu University, Varanasi 221 005

*Department of Physics, Dr H S Gour University, Sagar (M P ) 470 003

E-mail: rasinzh@yahoo.co.uk

Received 15 October 2006; accepted 1 May 2007

The near ultraviolet electronic absorption spectrum of 1,3,5 trifluorobenzene has been photographed on a 10.6 m concave grating spectrograph. The electronic forbidden transition 1A'2 ¬ 1A'1 is explained as arising due to perturbation of the electronic state by non-totally symmetric vibration n 6. Besides n 6 , the other modes of e' species n 8, n 9, n 18, and n 19 are also active and give rise to false origins. The vibrational frequencies for n 9, n 18, n 19, n 8, n 13, n 1 and n 16 modes in the first electronic excited state 1A'2 are reported for the first time.

Keywords: Electronic spectrum, Vibronic perturbations, Symmetric trifluorobenzene

IPC Code: G01J 3/42

 

 

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp 573-579

 

Acoustical behaviour of glycerine, dextrose and sucrose in Na2CO3 and
NaHCO3 buffer solution

A N Kannappan & R Palani*

Department of Physics, Distance Education Wing, Annamalai University , Annamalainagar 608 002

Received 19 April 2006; revised 3 August 2006; accepted 30 April 2007

The ultrasonic velocity, density and viscosity of glycerine, dextrose and sucrose in sodium carbonate (0.5 M) + sodium bicarbonate (0.5 M) buffer solutions at temperatures 303, 308 and 313 K have been measured.  The derived acoustical and thermodynamic parameters namely, adiabatic compressibility, free length, specific acoustic impedance, free volume, internal pressure, molar cohesive energy, viscous relaxation time, Gibb’s free energy, relative association, available volume, molal hydration number and Lennard Jones potential have been calculated. The variations of these parameters with respect to the molarity and elevation of temperature have been explained on the basis of solute-solvent interaction and structure forming tendency of the solutes in the solvents.

Keywords: Ultrasonic velocity, Viscosity, Specific acoustic impedance, Gibb’s free energy, Sucrose

IPC Code: B06B

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 580-590

 

Study of molecular interactions in binary mixtures of benzene-butanol and toluene-butanol systems from acoustic and thermodynamic parameters

Rita Mehra & Meenakshi Pancholi

Department of Pure & Applied Chemistry, M D S University, Ajmer 305 009

Received 22 November 2005, revised 18 April 2006, accepted 2 January 2007

Measurments of viscosity and density in conjunction with sound speed have been used for evaluating derived parameters for the binary system of benzene-butanol and toluene-butanol in the temperature range 298-318 K at an interval of 10 K. From these, excess parameters have been calculated. The variation of derived parameters as well as the sign and magnitude of corresponding excess functions has been used to investigate the type and extent of interactions between the component molecules of the binary liquid mixtures. The validity of various theoretical approaches of liquids has been tested for the system by comparing theoretical sound speeds with those experimentally determined over the entire composition range in the temperatures range 298-318K.

Keywords: Binary liquid mixtures, Thermoacoustic parameters, Benzene, Toluene and 1-butanol

IPC Code: B01J19/10

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 591-595

 

Growth and thermal studies of non-linear optical L-argininium diiodate
L-argininium dinitrate and L-argininium hydrochloride bromide single crystals

Preema C Thomas, S Arunaa, J Madhavan, Reena Ittyachanb, Joseph Arul Pragasamc,
Joe G M Jesudurai, K Prabha & P Sagayaraj*

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

bDepartment of Physics, S. H. College , Chalakudy, Kerala

cDepartment of Physics, Sathyabhama Engineering College , Chennai

dDepartment of Physics, Loyola College , Chennai 600 034

Received 11 July 2006; revised 13 November 2006; accepted 20 April 2007

Single crystals of L-argininium diiodate (LADI), L-argininium dinitrate (LADN) and L-argininium hydrochloride bromide (LAHClBr) were grown by slow solvent evaporation technique at room temperature. The grown crystals were characterized by X-ray diffraction, Differential Thermal Analysis (DTA), Thermogravimetric analysis (TGA) and Differential Scanning calorimetry (DSC). LADI crystallizes in the orthorhombic system, with space group P212121 . The XRD data prove that both LADN and LAHClBr crystals are monoclinic in structure with P21 space group. LADN is found to be thermally more stable than LADI and LAHClBr crystals.

Keywords: Growth from solution, Analogs of LAP, Non-linear optical, Differential scanning calorimetry, Microhardness

IPC Code: C30B

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 596-608

Effect of nickel substitution on structural, infrared and elastic properties
of lithium ferrite

S S Bhatu, V K Lakhani, A R Tanna, N H Vasoya, J U Buch, P U Sharma, U N Trivedi,
H H Joshi & K B Modi*

Department of Physics, Saurashtra University, Rajkot 360 005, India

*kunalbmodi2003@yahoo.com

Received 8 June 2006; revised 12 December 2006; accepted 9 April 2007

The structural and elastic properties of Li0.5(1-x)NixFe2.5-0.5xO4 (x = 0.0-1.0) spinel ferrite system have been studied by means of X-ray diffraction and infrared spectroscopic measurements at 300K. The X-ray diffraction data has been used to determine the lattice constant, X-ray density, distributions of cations among the tetrahedral and octahedral sites of spinel lattice, anion parameters, site radii, ionic radii, bond angle and bond length. The nature and change in the position of IR bands have been explained on the basis of cations involved in the system. The force constants have been used to calculate elastic moduli like bulk modulus, rigidity modulus, Young’s modulus, Poisson’s ratio, Debye temperature and corrected to zero porosity. The observed variation of elastic constants with nickel substitution has been explained on the basis of strength of interatomic bonding. The applicability of heterogeneous metal mixture rule for estimating elastic constants has been tested. The Debye temperature obtained from elastic constant data is higher than that of the X-ray diffraction analysis, mainly due to existence of peaks in the vibrational spectra at lower frequencies.

Keywords: Ferrites, Infrared spectroscopy, Elastic properties, Lithium ferrite, X-ray diffraction

IPC Code: G01J3/28

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 609-612

 

Temperature dependence of dielectric properties of sodium potassium
niobate ceramics

S C Bhatt, K Singh, M Uniyal, Om Prakash, Pankaj K Singh, R Saxena & B S Semwal

Department of Physics, H N B Garhwal University, Srinagar, Srinagar Garhwal-Uttaranchal 246 174

Received 21 August 2006; revised 31 January 2007; accepted 1 May 2007

Dielectric constant, loss tangent and electrical conductivity of Na0.5K0.5NbO3 (SPN) ceramic pellets have been measured at 10, 100 and 1000 kHz frequencies and at temperature varying from room temperature to 250° C. The dielectric constant increases with increase of temperature up to 190° C at all the three frequencies, and thereafter, it decreases with further increase of temperature, i.e., it shows a structural transition at about 190° C. The loss tangent also shows similar behaviour as dielectric constant shows. Some variations may be due to relaxation effects and impurities etc. around the sensitive transition region, which are seem to play prominent role in this soft mode region. Electrical conductivity increases with increase in temperature at all the three frequencies.

Keywords: Ceramics, Dielectric constant, loss tangent, Electrical conductivity

IPC Code: G01R 27/26

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 613-617

 

Solar selective properties of copper-aluminium composite films

 

T S Sathiaraj

Department of Physics, University of Botswana, P.B 0022, Gaborone, Botswana.

E-mail: sathiara@mopipi.ub.bw

Received 27 July 2006; revised 25 January 2007; accepted 30 April 2007

Composite films of copper and aluminium were deposited by reactive direct current co-sputtering of copper and aluminium. The number of copper pieces was varied during deposition which made it possible to vary the composition of the films. In order to understand the optical behaviour of the coatings, the optical constants were determined by fitting model dielectric functions to the transmittance and the near normal reflectance spectra in the wavelength range 300-2500 nm. The thicknesses of the layers obtained by modeling were confirmed by surface profilometry. The XPS studies of the samples reveal that the number of copper pieces used during co-sputtering control the formation of copper oxide. Computer simulations on layers of Cu-Al composites on metallic substrate with anti-reflection coatings were carried out to optimize solar absorptance using the optical data from the model. Solar absorptance as high as 0.91 with anti-reflectance coating was obtained from the simulation.

Keywords: Composite films, Solar absorptance, Computer simulations, Co-sputtering of Cu and Al

IPC Code: F24J2/00

 

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 618-623

 

Electrical and optical studies of corona poled 4-hydroxy-4¢ -nitroazobenzene doped polymethylmethacrylate films

 

Niraj Kalra, D K Chaturvedi, Sushil Kumar* & Sanjiv Arora*

Department of Physics, Kurukshetra University , Kurukshetra 136 119

*Department of Chemistry, Kurukshetra University , Kurukshetra 136 119

E-mail: dhiraj_chaturvedi@yahoo.co.in

Received 10 April 2006 ; revised 31 January 2007 ; accepted 24 April 2007

Guest-host polymeric systems with 4-hydroxy-4¢ -nitroazobenzene as guest and polymethylmethacrylate (PMMA) as host have been prepared by taking different concentrations of the guest and characterized by observing their electrical and optical behaviour. The prepared guest-host system has been found to have large band gap ~2.86 eV and transmission over visible range. Pure polymer (PMMA) was not found to show any observable electrical non-linearity whereas mixing of dye (guest) has shown remarkable effect on its non-linear electrical behaviour. Moreover, the model guest-host blend (4-hydroxy-4¢ -nitroazobenzene/PMMA) has been found to exhibit desired order of non-linearity by optimizing the concentration of guest, poling current and poling temperature.

Keywords: Polymethylmethacrylate films, Electrical properties, Optical studies, Molecular polarizability, Birefringence

IPC Code: C07B57/00

 

Indian Journal of Pure & Applied Physics

Vol. 45, July 2007, pp. 624-627

Photoelectric properties of CdS thin film prepared by chemical bath deposition

R Devi a, P Purkayastha b, P K Kalita a, R Sarmab, H L Das b & B K Sarma b

aDepartment of Physics, Guwahati College, & Guwahati-7810 21, Assam

 bDepartment of Physics, Gauhati University, & Guwahati-7810 14, Assam

Received 7 March 2006; revised 13 November 2006; accepted 4 January 2007

Cadmium sulphide thin films deposited on glass substrates are found to be polycrystalline having hexagonal type structure. The photocurrent-light intensity characteristics show sub-linear and super-linear behaviour which are attributed to the defects . The defect characterization is done from the temperature dependence of dc photoconductivity and rise and decay characteristics of the photocurrent. shallow levels (0.06 to 0.34eV) arising from interstitial cadmium or sulphur vacancies are found to cause extrinsic photoconductivity near room temperature whereas the deep levels dominate the rise and decay characteristics and superlinearity.

Keywords : CdS thin films, Photoconductivity, Activation energy, Super linearity

IPC Code: G03G 5/04