IOSR-JAP   Volume-3 ~ Issue-1 ~ Jan–Feb 2013

Paper Type	:	Research Paper
Title	:	Study of Dielectric Properties of Nano-crystalline Mn-Zn Ferrite
Country	:	India
Authors	:	Sunita Bhagwat*, Pratibha Rao
	:	10.9790/4861-0310106

Abstract: The ac conductivity σ and dielectric properties (dielectric constant ', dielectric loss '' and loss tangent tan δ) were measured as a function of frequency between 100 Hz and 20 MHz for the mixed ferrites ZnxMn1-xFe2O4 (where x = 0.2 to 0.8), synthesized by solid-state route. The ac conductivity σ below 1 MHz seems to be nearly frequency independent for all compositions; and above these frequency ranges, σ sharply increases until it reaches a maximum value. The relaxation time (τ) was found to be in the range 0.3x10-5 – 1.5x10-5sec from the hopping frequency. The dielectric constant for these ferrites is approximately inversely proportional to the square root of the resistivity. The electrical conduction mechanism was explained in terms of the electron hopping model. The formation of spinel structure and crystalline size was confirmed using X-ray diffraction (XRD) technique. Morphology of the samples was studied using Scanning Electron Microscopy (SEM).
Keywords: Solid-state route; spinel ferrite; dielectric properties; ac conductivity

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Paper Type	:	Research Paper
Title	:	Poly (vinylidene fluoride) Thin Film Prepared by Roll Hot Press
Country	:	Indonesia
Authors	:	Ambran Hartono, Suparno Satira, Mitra Djamal, Ramli, Edi Sanjaya
	:	10.9790/4861-0310711

Abstract: Various methods have been developed in the manufacture of Poly (vinylidene fluoride) (PVDF) thin films such as coating, spreading, evaporation and calendaring. The method of making this film certainly has many advantages and disadvantages as in the case of operational processes and also the cost of the required treatment. In this paper, an alternative method to preparation of PVDF thin films has been done through the development calendaring method by using roll hot press. The advantages of roll hot press are simple in terms of operation and relative low cost. PVDF thin film has been produced for several temperatures of roll hot press with several different thicknesses. The PVDF thin films are characterized using X-Ray Diffraction and IR spectra. In addition to determine the surface resistivity are caried out using I-V meter. We found that an increase in β fraction of PVDF thin films with increasing temperature at fixed film thickness, while the surface resistivity of PVDF film are decreased. This shown that the piezoelectric property of PVDF films has been improved.
Keywords: β fraction, piezoelectric, PVDF film, Roll hot press, Surface resistivity

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Obtained by Uniaxial Stretch, Materials Science Forum Vols. 514-516 (2006) pp 872-876
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[9] Y. Liu, Y. Sun, F. Zeng, Y. Chen, Q. Li, B. Yu, W. Liu, Morphology, Crystallization, Thermal, and Mechanical Properties of
Poly(vinylidene fluoride) Films Filled with Different Concentrations of Polyhedral Oligomeric Silsesquioxane, Polymer Engineering
and Science, 2012. DOI 10.1002/pen.
[10] B. P. Mahale, D. Bodas, S. A. Gangal, "Development of low-cost poly(vinyldifluoride ) sensor for low- pressure application," Micro & Nano Letters, 2011, Vol. 6 (7), pp. 40-542.

Paper Type	:	Research Paper
Title	:	The Effect of Sulfurisation Temperature on Structural Properties of CuAlS2 Thin Films
Country	:	Nigeria
Authors	:	A. U. Moreh, M. Momoh, B. Hamza
	:	10.9790/4861-0311217

Abstract: CuAlS2 thin films of the same thickness are deposited on suitably cleaned coning 7059 glass substrate by two stage vacuum thermal evaporation technique at room temperature and sulfurised at different temperatures. The structural properties studied by means of XRD revealed that the films are of crystalline in nature having tetragonal structure. For all the films the preferential orientation is [112]. The other orientations like [220], [312] and [400] were also observed in the films depending upon the sulfurisation temperatures. The values of lattice constants, grain size, micro strain and dislocation density of the films are calculated and the values agree strongly with ICDD data. Visual inspection of (SEM) micrographs of the films showed that crystallite size increase with increase in sulfurisation temperature.
Keywords: Dwell period, lattice parameters, Ramp rate, Sulfurisation, Thermal evaporation.

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