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Indian Journal of Pure and Applied Physics

 

 

 ISSN: 0019-5596

CODEN: IJOPAU 42 (8) 549-624

Volume 42

Number 8

AUGUST 2004

 

 

CONTENTS

 

Nuclear Physics

 

Spin-parity assignments to levels in the very - neutron - rich nucleus 113Rh

M Sainath*, K Venkataramaniah & P C Sood

 

553

Atomic and Molecular Physics

 

Spectroscopic and transport studies of Cu2+ doped in (30-x) Na2O-xNaF-50B2O3-20Bi2O3 glass system

Swapna S Suresh & V Chandramouli*

560

 

Mechanisms inherent in the thermoluminescence processes

J Prakash*, S K Rai, P K Singh & H O Gupta

565

 

Infrared spectra of charge transfer complexes of bis (N phenylsalicyl- aldiminato) CuII

J H Prajapati, S G Patel* & A T Oza

572

 

Crystal and molecular structure of antimony thiourea bromide

V Shettigar, S G Bhat & S M Dharmaprakash*

581

 

FT-Raman, FTIR spectra and normal coordinate analysis of 5-bromo-2-nitropyridine

N Sundaraganesan*, S Ilakiamani, H Saleem & S Mohan*

585

 

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

 

Ultrasonic study of human cerebrospinal fluid

L Palaniappan* & V Velusamy

591

 

Acoustic behaviour of plastics for medical applications

Jyoti Lochab & V R Singh*

595

 

Effective thermal conductivity of two-phase systems with cylindrical inclusions

Jagjiwanram & Ramvir Singh*

600

 

 

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

 

Electrical, optical and structural properties of indium-antimonide (In-Sb) bilayer film structure

M Singh* & Y K Vijay

610

 

Space charge limited conduction in Se80-xTe20Agx thin films

S P Singh*, S Kumar & A Kumar

615

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

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 42, August 2004, pp 553-559

 

Spin-parity assignments to levels in the very-neutron-rich nucleus 113Rh

M Sainath, K Venkataramaniah & P C Sood

 

Spins and parities have been assigned to the low-lying energy levels in the very neutron-rich Z=45 nucleus 113Rh identified in beta decay of the exotic fission fragment 113Ru. The assignments are based on the experimental b intensities and log ft values, gamma energies, intensities, branchings and multi-polarities deduced from 113Ru decay, taken together with the trends for the analogous levels and their comparative feedings and decays in the lighter n-rich Rh isotopes with A=105-111, and the supporting model considerations. No abrupt pattern changes are noticed for this N=68 nucleus lying just beyond the N=66 mid shell point. Whereas the low-lying positive parity level energies show very little variation or a slow decreasing trend, the negative parity level energies are seen to rise sharply with the addition of successive neutron pairs. The intruder band, having reached minimum energy in the N=64 isotope109Rh, appears to have a parabolic increase on either side.

 

[Keywords: 113Rh Beta decay, Rh isotopes level systematics, 113Rh levels spin parities assignments]

IPC Code: G 01 T 1/16

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 42, August 2004, pp 560-564

 

Spectroscopic and transport studies of Cu2+ doped in
(30-x)Na2O-xNaF-50B2O3-20Bi2O3 glass system

Swapna S Suresh &V Chandramouli

 

ESR, optical absorption, IR and dc electrical conductivity of (30-x)Na2O-xNaF-50B2O3-20 Bi2O3 glass system have been investigated. From infrared results, it is observed that the glass is made up of [BO3] and [BO4] units and in fluorine rich glass B-F bonds are formed. ESR results show that Cu2+ has tetragonal distorted octahedral coordination and its ground state is dx2-y2. The observed changes in spin-Hamiltonian parameters with increasing concentration of NaF can be attributed to the decrease in the field strength at Cu2+ ion site .The decrease in a value can be attributed to decreasing ionic character of the glass. The existence of maxima of optical absorption at x =18 mole% of NaF is attributed to the formation of BO2F2 structural units. The dc electrtrical conductivity studies show that mobile ions are Na+ and the activation energy is attaining a maximum value at x =18 mole% of NaF characterizing a mixed anion effect.

 

[Keywords: (30-x) Na2O-x NaF-50 B2O3-20 Bi2O3 , Spectroscopic properties, Electrical conductivity, Glass]

IPC Code: G  01  J  3/12

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 42, August 2004, pp 565-571

 

Mechanisms inherent in the thermoluminescence processes

J Prakash, S K Rai, P K Singh & H O Gupta

 

Mechanisms inherent in the thermoluminescence (TL) processes are re-investigated with an aim to establish a generalized approach. It has been observed that the extents of recombination and simultaneous retrapping decide the order of kinetics involved. First order kinetics has been found to be a recombination dominant process with negligible or no retrapping. Probabilities of recombination and retrapping are found to be equal in second order kinetics. With the increasing order of kinetics, the extent of recombination decreases alongwith a simultaneous increase in the retrapping. A generalized equation has been developed which is found to be capable of representing the intensities of TL glow curves of different orders of kinetics including that of the first order. It has been found that irrespective of the order of kinetics involved, TL intensity decays exponentially.

 

[Keywords: Thermoluminescence, Kinetics]

IPC Code: F 21 K 2/04

 

 

 

Indian Journal of Pure & Applied Physics

Vol. 42, August 2004, pp 572-580

 

Infrared spectra of charge transfer complexes of bis(N-phenylsalicylaldiminato) CuII

J H Prajapati*, S G Patel & A T Oza

 

The charge transfer complexes of bis(N-phenylsalicylaldiminato) CuII with organic acceptors like TCNQ, TCNE, TNF, DDQ, chloranil, and iodine are prepared and studied with Fourier transform infrared spectroscopy. The spectrum of the donor chelate shows systematic steps in transmission above 2500 cm-1, which are analyzed by its first-derivative. Fine structure is also seen pronounced in the charge transfer complexes. Two or three electronic absorption envelopes are identified in all the complexes. The nature of transitions (whether direct or indirect), band tailing effects and free-carrier absorption are also analyzed. TNF complex shows free-carrier absorptions in a very wide range above 1800 cm-1.

 

[Key words: Charge transfer complexes, Pierls semiconductor, Salicylaldiminato, Infrared spectra, Optical conductivity, Infrared spectra, Band assignment]

IPC Code: G01N 30/96

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 581-584

 

Crystal and molecular structure of antimony thiourea bromide

V Shettigar, S G Bhat & S M Dharmaprakash

 

The structure of antimony thiourea bromide hydrate (ATB) with molecular formula Sb[SC(NH2)2]2Br3.H2O has been determined by X-ray single crystal diffraction. ATB crystallizes in the orthorhombic system with the lattice parameters = 12.272(3); b =11.675(4); c =18.617(5); the space group is Cmc21, Z = 8, and Dc = 2.648Mg/m3. The final R = 0.0366 (wR = 0.0914) for 1273 reflections. The asymmetric unit consists of two symmetrically independent halves of a complex Sb[SC(NH2)2]2Br3] and one crystal water molecule which are completed to a complex dimer by the mirror plane of the space group. The whole crystal is found packed in mm2 point group, which is non-centrosymmetric arrangement of atoms.

 

[Keywords: Crystal and molecular structure, Antimony thiourea bromide, Non-linear optical]

IPC Code: G11B 7/00

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 585-590

 

FT-Raman, FTIR spectra and normal coordinate analysis of 5-bromo-2-nitropyridine

N Sundaraganesan, S Ilakiamani, H Saleem & S Mohan*

 

The Fourier Transform-Raman and Fourier Transform-Infrared spectra of 5-bromo-2-nitropyridine have been recorded. The observed frequencies were assigned to various modes of vibrations on the basis of normal coordinate calculations, assuming CS point group symmetry. The potential energy distribution associated with normal modes is also reported here. The assignment of fundamental vibrations agrees well with the calculated frequencies.

 

[Keywords: FT-Raman and FTIR spectra, Normal coordinate analysis, 5-Bromo-2-nitropyridine]

IPC Code: G 01 J 3/28

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 591-594

 

Ultrasonic study of human cerebrospinal fluid

L Palaniappan* & V Velusamy

 

Human cerebrospinal fluid (CSF) has been is collected from various individuals of both sex including infants. Sound velocity and density have been measured in these samples and acoustical properties such as adiabatic compressibility and acoustic impedance have been calculated. The observed variations have been used to interpret the possible interaction among the components of CSF. It has been found that age and sex play an important role in deciding the sound velocity in CSF. The restriction in wave propagation is observed due to the change of structure of protein molecules of CSF. A specific reduction in sound velocity is observed in aged female subjects, which has been attributed to the increase in specific protein AZ 68. lack of estrogen is reflected in CSF analysis.

 

[Keywords: Ultrasonics, Cerebrospinal fluid]

IPC Code: G 10K 11/00

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 595-599

 

Acoustic behaviour of plastics for medical applications

Jyoti Lochab1 & V R Singh2

 

The rectangular and square samples of bio-plastic materials namely, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene plastic (PS material), polypropylene (PP), polyvinyl chloride (PVC), bakelite (G-10), nylon, Y-dent and teflon (PTFE) used for different applications in hospitals have been studied. These samples collected from different hospitals in Delhi (Safdarjang Hospital, Batra Hospital, AIIMS) have been studied for ultrasonic velocity, elasticity, acoustic impedance etc. at room temperature (24C). The average values of ultrasonic velocity and elasticity are found to vary directly with the density. The ultrasonic parameters measured at 2.5 MHz are reported here.

 

[Keywords: Ultrasonic properties, Acoustic impedance, Medical plastics, Transmission coefficient]

IPC Code: G 10K 11/00

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 600-609

 

Effective thermal conductivity of two-phase systems with cylindrical inclusions

Jagjiwanram & Ramvir Singh*

 

A theoretical model is presented to predict effective thermal conductivity of real two-phase materials from the values of thermal conductivity of the constituent phases and their volume fractions. Two-phase materials have been assumed to contain cylindrical particles arranged in a regular three-dimensional cubic geometry. The arrangement has been divided into unit cells, each of which contains a cylinder. The resistor model has been applied to determine the effective thermal conductivity (ETC) of the unit cell. A porosity correction term F is introduced in order to incorporate varying individual geometries and non-linear flow of heat flux lines generated by the difference in thermal conductivities of constituent phases. Theoretical calculations of the ETC have been carried out on a large number of samples and comparisons have been made with other models and experimental values cited in the literature. The values predicted by the proposed model are in close agreement with experimental values and more accurate than those obtained from existing models.

 

[Keywords: Correction term, Cylindrical inclusions, Effective thermal conductivity, Real two-phase systems, Unit cells]

IPC Code: G 01 N 25/18

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 610-614

 

Electrical, optical and structural properties of indium-antimonide(In-Sb)
bilayer film structure

M Singh & Y K Vijay

 

The indium-antimonide having small band gap is an important material for IR detectors and sources. The In-Sb thin film was deposited on glass substrate in the high vacuum chamber at pressure 10-5 torr. The samples were annealed for three hours on two different temperatures. The electrical resistivity decreases with increasing temperature, shows the semiconducting behaviour. The optical band gap varies from 0.22 to 0.23 eV with annealing temperature. The observed positive thermoelectric power indicates that In-Sb thin films were p-type in nature. The Rutherford back scattering analysis shows that the inter-diffusion concentration varies with temperature and X-ray diffraction pattern shows the improvement of crystallinity with annealing temperature.

 

[Keywords: In-Sb, Band gap, electrical resistivity, optical band gap]

IPC Code: C 03 B 25/00

 

 

 

Indian Journal of Pure & Applied Physics

 Vol. 42, August 2004, pp 615-620

 

Space charge limited conduction in Se80-xTe20Agx thin films

S P Singh & S Kumar and A Kumar

 

The dc conductivity measurements at high electric fields in vacuum evaporated thin films of amorphous Se80-xTe20Agx  (x=0,5,10,15) have been reported. The current-voltage (I-V) characteristics have been measured at various fixed temperatures. In all the samples ohmic behaviour is observed at low electric fie lds. However, at high electric fields (E~104V/cm), non- ohmic behaviour is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in all the glassy materials studied in present case. From the fitting of the data in the theory of SCLC, the density of defect states near the Fermi level is calculated. It is concluded from the results obtained that the density of defect states do not change significantly with increasing concentration of Ag in the pure binary Se80Te20 system.

 

[Keywords: dc Conductivity, Se80-xTe20Agx thin films, Space charge limited conduction]

IPC Code: G 01R