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Journal Cover Research & Reviews : Journal of Physics
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   Full-text available via subscription Subscription journal
     ISSN (Print) 2278-2265 - ISSN (Online) 2278-2265
     Published by STM Journals Homepage  [41 journals]
  • Field Dependence of Third Order Perturbed Energy of Cobalt Ferrite Thick
           Films
    • Authors: P. Samarasekara
      Abstract: Third order perturbed classical Heisenberg Hamiltonian was modified to describe the variation of magnetic properties and easy axis orientation of cobalt ferrite films with applied magnetic field and number of layers of the film. According to our theoretical studies explained in this manuscript, the magnetically easy and hard directions of cobalt ferrite films solely depend on in plane and out of plane magnetic fields. According to 3-D and 2-D plots, there are many easy and hard directions at one particular value of in plane or out of plane magnetic field. The magnetic properties were investigated for cobalt ferrite films with thickness up to 10,000 unit cells. The total magnetic energy was calculated for a unit spin of cobalt.

      Keywords: Heisenberg hamiltonian, Cobalt ferrite, Perturbation
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Optical Properties of SiO2 Nanoparticles Doped PEO-LiClO4 Nanocomposite
           Polymer Electrolyte Films
    • Authors: Shishir U. Patil, S. S. Yawale, S. P. Yawale
      Abstract: The optical transmission and absorption spectra were recorded in the wavelength range 200-800 nm for optimized high conducting concentrations of SiO2 nanoparticles in PEO-LiClO4 -m wt% SiO2 polymer matrix. Values of absorption coefficient, direct band gap energy, measure of extent of band trailing or Urbach energy, absorption edge and constant, B, have been investigated by optical characterization method. Effect of concentration of SiO2 nanoparticles in the polymer matrix on these parameters has been discussed. It has been observed that addition of SiO2 nanoparticles increases structural disorder and fluctuations of the internal fields associated with it. Small change in the concentration of SiO2 nanoparticles changes optical properties of nanocomposite polymer matrix. It was also found that direct band gap fits in the lower energy region of fundamental absorption edge.

      Keywords: Absorption coefficient, Optical energy gap, Optical properties, Absorption edge, Urbach energy, Bang trailing, Nanocomposite polymer matrix
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Spectral Analysis and Estimation of Depths to Magnetic Rocks below the
           Katsina Area, Northern Nigerian Basement Complex
    • Authors: Sabiu Bala Muhammad, E. E. Udensi, M. Momoh, Y. A. Sanusi, T. Suleiman, O. Ajana
      Abstract: Airborne magnetic data over the Katsina area of the Northern Nigerian Basement Complex were analyzed and interpreted in this study. The study area covers parts of the Northern Nigerian Basement Complex, bounded by longitudes 7000’ and 80 30’; and latitudes 12030’ and 13030’. Regional-Residual Separation was carried out using Least Square Method. The resulting regional map revealed a regional trend in the NE-SW direction. The magnetic residual values ranged from -329.74 nT to 202.91 nT. Method of spectral analysis was applied to the residual data. The result revealed two distinct layers. The first layer which occupies the high frequency tail is due to the effects of shallower ensembles of magnetic sources and noise in the data. The first layer depth ranges from 0.04 km to 0.74 km. The second layer is associated with the intermediate frequencies and lies between the depths of 0.1 km and 0.80 km. The lowest depth of 0.1 km occurred.Keywords: Spectral analysis, Katsina area, Basement complex
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Structural Properties and DC Conductivity Study of Barium Hexaferrite
           Powder
    • Authors: Rajshree B. Jotania, Atashi Ajmera, Rajshree Jotania
      Abstract: M-type barium hexaferrite powder with chemical composition BaFe12O19 has been synthesized using Co-precipitation method. High purity Nitrates, Oxides and Carbonates of Iron (III), Barium (II) and Ammonium Hydroxide were used as starting materials. The prepared precursors calcined at temperature 950 °C for 4 h in a furnace and characterized by FTIR, SEM, XRD, TGA and DC conductivity measurements. Microstructure of prepared samples was observed via SEM. X-ray diffraction studies confirm the presence of a single phase with the theoretical space group P63/mmc barium hexaferrite (BaM), which crystallizes in the hexagonal system and has a uniaxial magnetoplumbite structure, displays good chemical stability and structural properties.Keywords: Barium hexaferrite, XRD, SEM, TGA
      PubDate: 2014-05-08
      Issue No: Vol. 3 (2014)
       
  • Structural and Dielectric Properties Hexaferrite/Poly (Vinyl Alcohol)
           Composites
    • Authors: Amrin Kagdi, Rajshree B. Jotania
      Abstract: Magnetic barium cobalt hexaferrite particles-PVA composites with of different mass ratio:  9:1, 8:2, 7:3, 6:4 and 5:5 were prepared. Structural properties of the composites were characterized by Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The effect of the concentration of Ba2Co2Fe28O46 hexaferrites on structural and dielectric properties of magnetic-PVA  composites were investigated. FTIR result revealed  that composite samples show absorption peaks of both ferrites and PVA. The X-ray diffraction investigations confirm the formation of mono phase of hexaferrite particles. Scanning electron microscopy images reveal that the shape and size of barium cobalt hexaferrite powder particles is irregular. The addition of PVA not much changed the shape and  size of particles  (ranging from 200-300 nm) but porosity found to decrease.  

      PubDate: 2014-01-16
      Issue No: Vol. 2 (2014)
       
  • Orientation of Easy Axis of Ferromagnetic Films as Explained by Third
           Order Perturbed Heisenberg Hamiltonian
    • Authors: P. Samarasekara, Prabhani Rajakaruna
      Abstract: The third order perturbed Heisenberg Hamiltonian has been applied to explain the magnetic easy axis orientation. Ferromagnetic CoPt/AlN multilayer thin films with number of layers N=11, 16 and 21synthesized on fused quartz substrates using dc magnetron sputtering technique have been employed as experimental data. According to experimental research performed by some other researchers, easy axis of these fcc structured ferromagnetic films is oriented in the plane of the film above one particular temperature. Average value of out of plane spin component was plotted against temperature in order to determine the spin reorientation temperature. The spin reorientation temperature was highly sensitive to 2nd order magnetic anisotropy constant.
      PubDate: 2014-01-16
      Issue No: Vol. 2 (2014)
       
  • Deconvolution of X-ray Diffraction Spectrum of Polypropylene
    • Authors: B. Sanjeeva Rao, N. Maramu, Venkateswar Rao, N. Srinivasa Rao, K. Rajendra Prasad
      Abstract: Deconvolution methods have been used to evaluate degree of crystallinity and particle size from diffractogram of polypropylene(PP). The deconvolution method is used to separate the various peaks from the total XRD spectrum and it is successful in separating the crystalline, amorphous and background regions of a diffractogram. The degree of crystallinity of PP is calculated to be 49%. The particle size of crystallites in different crystalline phase is calculated using Scherrer equation. 
      PubDate: 2014-01-16
      Issue No: Vol. 2 (2014)
       
  • Studies on Electrical and Thermal Transport of InN based on Two Layer
           Model
    • Authors: A. Chakraboerty, B. Sharma, C. K. Sarkar
      Abstract: InN, a material of huge potential in device applications, is grown on sapphire substrate. But due to the high lattice mismatch between the sapphire and InN, the large number of dislocations develops near the interface between the two materials. However, the density of threading dislocation falls sharply in the bulk layer. The charge density has also similar variation. Therefore, the bulk InN crystal may be treated to be consisting of two layers, one the interfacial layer where the density of dislocations is very high and the layer on the interfacial layer, called bulk layer which has much lower density of dislocation and is considered to be negligible. We have calculated the mobility of InN and Seebeck Coefficient of InN based on the two layer model. We find that the theoretical values of mobility based on two layer model matches quite well with the experimental data.  In our model, in the interfacial layer, the dislocation scattering and ionized impurity scattering mechanisms are considered to be the dominating scattering mechanisms while for the bulk layer, the acoustic phonon scattering via deformation potential and piezo electric coupling, ionized impurity scattering and optical phonon scattering mechanisms are considered. The theoretical values of the thermoelectric power of InN, calculated on the basis of two layer model are found to be in good agreement with experimental data. 
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • In Plane Oriented Strontium Ferrite Thin Films Described by Spin
           Reorientation
    • Authors: Pubudu Samarasekara, Udara Saparamadu
      Abstract: For the first time, in plane orientation of magnetic easy axis of sputtered strontium hexaferrite thin films has been explained using modified Heisenberg Hamiltonian model with stress induced anisotropy term. The variation of average value of in plane spin component with temperature was plotted in order to determine the temperature at which easy axis is oriented in the plane of the strontium ferrite film. The average value of in plane spin component in this 2-D model reaches zero at one particular temperature. This particular temperature obtained using our theoretical model agrees with the experimental value of the temperature of rf sputtered polycrystalline strontium ferrite thin films deposited on polycrystalline Al2O3 substrates (500°C). This spin reorientation temperature solely depends on the values of energy parameters used in our modified Heisenberg Hamiltonian equation.   
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • Fast Asymmetric MHD Modes in Structured Media with Steady Flows
    • Authors: A. Satya Narayanan, V. S. Pandey
      Abstract: The effect of steady-flows on fast kink waves amplitude as well as on its heating rate profile are examined in inhomogeneous layers. We assume the equilibrium magnetic and plasma configuration  as a slab-geometry: z-axis of the slab is along the uniform background magnetic field. We allow density stratification perpendicular to the direction of background magnetic field. In this study we evaluate the extent to which fast kink waves can be collisionally dissipated and their dissipation by viscosity and heat conduction invoking the presence of a steady flow and compare the results with the minimum required optically thin radiative cooling rate. Only body waves exist for the field-aligned propagation. However, surface wave is present along with body waves for oblique propagation. We find that steady-flows have negligible effect on surface waves. However, it modulates the wave amplitude and thereby heating rate profile of body waves. The steady flow shows opposite behaviour on the field-aligned propagating fast body waves than obliquely propagating body waves. In the case of field-aligned propagation the anti-parallel flows increases both the wave amplitude and heating rate as compared to parallel flows. However, for the oblique propagation we get the opposite pattern. The obliquely propagating kink body waves are more effective in heating as compared to field-aligned propagating kink body waves. We have also studied the wave and heating profile of shear kink waves propagating principally almost normal to the interface. We find that the transverse components (i.e., ) of shear surface waves are equal and it is larger than the longitudinal component (i.e., ) by three orders of magnitude. 
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • Binding Energy and Energy Level with B(E2; 0ـــ2) of
           Neutron-Rich 60-66Fe Isotopes using NuShellX
    • Authors: F. I. Sharrad
      Abstract: Binding energy of the ground state, energy levels and B(E2; ) values for even-even Fe isotopes with proton number Z=26 and neutron numbers (n) between 34 and 40  have been calculated through shell model calculations using the shell model code NuShellX for Windows by employing harmonic oscillator (HO) model space and the GXPF1A, KB3G and FPD6 interactions. The binding energies calculations are reasonably consistent with the available experimental data. The predicted low-lying levels (energies, spins and parities) are in good agreement with newly experimental data, and by employed FPD6 for 60Fe nucleus, GXPF1A for 62Fe nucleus and KB3G for 64,66Fe nuclei. Furthermore, B(E2; ) values are in good agreements with available experimental data. 
      PubDate: 2013-09-09
      Issue No: Vol. 2 (2013)
       
  • Measurement of Radon Exhalation Rate from Building Materials
    • Authors: F. Shoqwara, N. Dwaikat, G Saffarini
      Abstract: Indoor radon has been recognized as one of the health hazards for mankind because long-term exposure to radon increases the risk of developing lung cancer. This study aims at assessing the contribution of building materials towards the total indoor radon exposure to the inhabitants of Nablus district, Palestine. The radon exhalation rate has been carried out for different building materials of international origin used in construction in Nablus district. The “closed-can technique” has been employed in this study using solid state nuclear track detectors (CR-39). After 100 days of exposure, CR-39 detectors were etched chemically and then counted under an optical microscope. Results show that Radon exhalation rates from granite and marble have relatively high values as compared to other building materials followed- in order- by cement, ceramic, concrete, building stones, and porcelain, while gypsum, sand, gravel and bricks contribute less to radon exhalation rate which was found to range from (55.37 ± 15.01) mBq/m2h for gypsum samples to (589.54 ± 73.24) mBq/m2h for granite samples, with a total average value of (268.56 ± 166.21) mBq/m2h. The corresponding radon concentration, effective radium content, and annual effective dose average values were (148.49 ± 91.13) Bq/m3, (1.93 ± 1.20) Bq/Kg and (3.74 ± 2.30) mSv/y, respectively. In general, the radon exhalation rate from the investigated building materials is low and under the global value except for granite, marble and some cement samples and thus except for the excluded, the studied materials are safe as construction materials.  
      PubDate: 2013-04-16
      Issue No: Vol. 2 (2013)
       
  • Breakdown of Physicothermodynamic System of The Human Neural Network in
           The Fractional Dimensional Space Due To Z+ Bis Intake: Introduction to
           Photonic & Phononic Nociceptions
    • Authors: Tuhin Dutta, Deepak Kumar, Madan Mohan Bajaj, Sobinder Singh
      Abstract: Nociceptionics deals with the properties, dynamism of nonciceptons, emitted from the quasi-particles of pain perception due to killing or annihilation of living organism in any part of the globe. The new subject of Nonciceptonics is analogous to the conventional discipline of Digital & Pulse Electronics and Abstract Algebra. In our present work we will study the characteristics of fractional dimensional space in the human brain as a severe consequence of the nociceptons emitted from the living organism while being killed or annihilated. We shall provide the relevant numerical calculations using the various characteristics of nociceptons. We have explained our views in half dimensional space. 
      PubDate: 2013-04-16
      Issue No: Vol. 2 (2013)
       
  • Ultrasonic Study of Molecular Interactions in Organic Liquids at Various
           Temperatures and Concentrations
    • Authors: Rethika K T
      Abstract: The ultrasonic velocity was measured for water and glacial acetic acid in their pure state and in their binary mixtures.  The ultrasonic velocity was measured also for the solution of salicylic acid in glacial acetic acid. Relative density and relative viscosity were also measured at various temperatures and concentrations. The parameters like adiabatic compressibility, acoustic impedance, relaxation time and attenuation were determined. This study is helpful for the understanding of the macroscopic structure solute–solute and solute–solvent interactions. 
      PubDate: 2013-02-12
      Issue No: Vol. 2 (2013)
       
  • Relationship between Demagnetization Factor and Energy of Thick
           Ferromagnetic Films
    • Authors: P. Samarasekara
      Abstract: The variation of energy of ferromagnetic thick films of 10000 layers with demagnetization factor will be described in this report using second order perturbed Heisenberg Hamiltonian. Under the influence of demagnetization factor given by =6.6, the sc(001) film with 10000 layers can be easily oriented in 0.6 radians direction for the values of energy parameters used in this report. Easy direction of thick fcc(001) film with 10000 layers was determined as 0.66 radians, when the demagnetization factor is given by=2.6.  The energy of sc(001)thick film is larger than that of fcc(001) thick film. But the energy curve of fcc(001) thick film is smoother than that of sc(001). 
      PubDate: 2013-02-12
      Issue No: Vol. 2 (2013)
       
  • The problem involving the quantification of quantum discord
    • Authors: Amit Bhar, Sujoy Das
      Abstract: Last few years people are concentrating in studying the different aspects of non-locality of quantum mechanics. Many correlation measures have been introduced and well studied. Quantum discord is one of such correlation measure that creates new challenges among the physicists and mathematicians. New quantification of quantum discord is one of the fascinating area. In this paper we study for the investigation of the difficulties in finding the analytic expression of quantum discord. 
      PubDate: 2012-08-06
      Issue No: Vol. 2 (2012)
       
  • Study of size controllable synthesis of indium tin oxide nano particles
           and its different characterization.
    • Authors: C. Sanjeeviraja
      Abstract: Nanocrystalline Indium oxide powders were prepared by Combustion synthesis. The changes of nanostructure caused by material processing were studied using X ray powder diffraction (XRD), Transmission Electron Microscopy (TEM) Selected Area Electron Diffraction (SAED) and Brummer Emette Teller Analysis (BET). The stoichiometric composition of the starting indium tin oxide powder (cubic in traces) induced phase transitions to high temperature. We found that the phase transition to ITO was initiated at the surface of the small particles, while transition from cubic to rutile started in their center. Changes in crystallite size during annealing process were obtained by the Scherer method, while the particle size changes were monitored by TEM. A difference in the results obtained by this combustion technique was explained in frame of basic physical properties characterizing both methods.
      PubDate: 2012-08-06
      Issue No: Vol. 2 (2012)
       
  • Demagnetization Factor Dependence of Energy of Ultrathin Ferromagnetic
           Films with Four Layers
    • Authors: P. Samarasekara
      Abstract: The variation of energy with demagnetization factor will be investigated for sc(001) and bcc(001)ferromagnetic lattices with four layers using classical model of Heisenberg Hamiltonian. According to3-D plots, the films with four layers can be easily oriented in certain directions under the influence ofparticular demagnetization factor and angles for both sc(001) and bcc(001) ferromagnetic latticestructures. A flat part can be seen in the middle of 3-D plots in addition to periodic variations. When thedemagnetization factor is given byƒÝ ƒç 0d N= 6, sc(001) film with four layers can be easily oriented in0.6 radians direction for the energy parameter values used in this simulation. Under the influence ofdemagnetization factor given byƒÝ ƒç 0d N= 5.2, thin film of bcc(001) lattice with four layers can be easilyoriented along 0.63 radians direction.

      PubDate: 2012-08-06
      Issue No: Vol. 2 (2012)
       
  • The Relation between Double Laplace Transform and Double Hankel Transform
           with Applications II
    • Authors: Yashwant Singh, Harmendra Kumar Mandia
      Abstract: The object of this paper is to establish a relationship between the double Laplace transform and the doubleHankel transform. A double Laplace-Hankel transform of the product of H-functions of one and two variablesis then obtained. Application of our main result, summation formula and some interesting special cases havealso been discussed.

      PubDate: 2012-04-03
      Issue No: Vol. 2 (2012)
       
  • Dependence of Fidelity of Quantum Teleportation for Pure State on Degree
           of Entanglement
    • Authors: J. K. Sharma, Sushamana Sharma, Rajshri Vyas
      Abstract: Quantum information and computation has been a rapidly evolving field. As Landauer pointed out, information is physical, so it should not look strange to try to bring together quantum mechanics and information theory. Indeed, it was soon realized that it was possible to use the laws of quantum physics to perform tasks which are unconceivable within the framework of classical physics like quantum teleportation, superdense coding, quantum cryptography, Shor’s factorization algorithm or Grover’s searching algorithm. Here, quantum teleportation has been discussed in a different way for two qubit pure state. It is a well-known fact that any two qubit pure states can be decomposed into two parts – pure entangled part and factorizable part. The square of the weightage of entangled part (p) gives the amount of entanglement in the state. It has been shown that the fidelity of quantum teleportation is a function of p and its variation with p has been plotted for all the possible outcomes.

      PubDate: 2012-04-03
      Issue No: Vol. 2 (2012)
       
  • Determination of Magnetic Properties of Cobalt Films Using Second Order
           Perturbed Heisenberg Hamiltonian
    • Authors: P. Samarasekara, Amila D Ariyaratne
      Abstract: The magnetic properties of hexagonal closed packed structured ferromagnetic cobalt films were investigated by means of second order perturbed Heisenberg Hamiltonian. First the number of nearest neighbors and the constants arisen from the partial summation of the dipole interactions of the structure of cobalt were calculated using some special algorithms. Minimization of the energy difference between the easy and hard direction of a memory device is very important. When the energy difference between the easy and hard directions is significantly small, the magnetic moments in a memory device can be quickly rotated between easy and hard directions under the influence of a small magnetic field. The thickness of a cobalt film corresponding to this minimum energy difference calculated using this theoretical model agrees with some experimental data of cobalt-based magnetic memory devices.
      PubDate: 2012-04-03
      Issue No: Vol. 2 (2012)
       
  • Comparative Study for Structure of Alkali Borate Glasses with and without
           Aluminum Oxide – Density Measurements
    • Authors: Neetu Chopra, N. P. Singh, Gopi Sharma
      Abstract: This paper reports on density measurements of alkali aluminoborate glass system (xR2O − yAl2O3 − (1 − x − y)B2O3, R = Li, Na where x = 20 or 30 mol% and y = 10 or 15 mol%), correlated with the glass structure. The samples have been prepared by using the melt-quenching technique. The density has been obtained by Archimedes principle using benzene as buoyant. The effect of nature of alkali and its composition with and without alumina is well studied. It is found that number of trigonal and tetrahedral boron units are related to the type of alkali oxide as well as the total concentration of alkali oxide in alkali borate glasses. The addition of aluminum oxide at the cost of borate induces the changes in the structure of glass network which further depends upon aluminum oxide and alkali oxide content.
      PubDate: 2012-04-03
      Issue No: Vol. 2 (2012)
       
 
 
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