IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 10, 2015 | ISSN (online): 2321-0613
Preparation and Characterization of (Bi1.65Pb0.35 )2Sr2Ca2Cu3O10+δ Superconductor Chirag J. Shah1 Hemin V. Thakkar2 Shailesh M. Gandhi3 1,2,3 Department of Mechanical Engineering 1,2,3 Government .Polytechnic, Ahmedabad-380015 Abstract— The (Bi1.65Pb0.35 )2Sr2Ca2Cu3O10+δ type high temperature superconductor compounds have been synthesized by solid state reaction method and characterized by structural and superconducting properties. Four-probe resistivity confirmed the superconducting transition temperature of 102K.The X-ray diffraction patterns revealed tetragonal structure. The effects of modified sample preparation on structural, surface and superconducting properties are presented. Key words: High Temperature Super Conductor, X-ray Diffraction, Transition Temperature, etc.
III. RESULTS AND DISCUSSION
I. INTRODUCTION
Fig. 2 shows the powder X-ray diffractogram of (Bi1.65Pb0.35 )2Sr2Ca2Cu3O10+δ superconductor. All the peaks are corresponding to single phase tetragonal crystal structure. Majority of the peaks are indexed to be of Bi-2223 phase. Excellent phase purity is seen in XRD. The lattice parameters determined from the X-ray pattern are a=5.392 A0,b=5.392 A0 and c= 37.01 A0. The full width at half maximum (FWHM) of the peak are sharp ~0.03 0, suggesting the grain growth due to high temperature annealing. The average crystallite size estimated from the X-ray pattern was of the order of 0.2 µm.
There has been a growing interest in the High temperature superconductors (HTSC) due to their applications as lossless current leads for magnets, levitation etc. Several cuprate oxides such as REBa2Cu3O7-δ [1] (RE=Y and rare earths, Tc = 90 K), Bi2Sr2Ca2Cu3O10+δ [2] (Bi-2223, Tc = 110 K) and HgBa2Ca2Cu3O8+δ [3] (Hg-1223, Tc = 164 K) have been discovered since 1987. Not many reports available on phase pure, homogeneous samples with reproducible superconducting properties. For meaningful applications of HTSC, easy fabrication techniques for its large scale production are required. In this paper we report on the preparation of Bi2223 by solid state reaction route. The method was shown to produce homogeneous, single phase materials. We report the structural characterization of Bi-based cuprate type material. Crystal structure of this material was obtained by a high resolution X-ray powder diffraction which provides clearcut evidences of the formation of this compound in tetragonal structure. Whereas most of the Bismuth cuprates can be prepared relatively easily compare to chemical method, devoid of any major impurity phases with a Tc close to 108K.
Fig. 1: Flow chart showing the sample preparation
II. EXPERIMENTAL PROCEDURE The sample of the (Bi1.65Pb0.35 )2Sr2Ca2Cu3O10+δ was prepared by solid-state reaction method. The high purity (99.9+ % pure) starting compounds of Bi2O3, PbO, SrCO3, CaCO3and CuO were taken in stoichiometric quantities and ground thoroughly under acetone to form a homogeneous mixture. This mixture was calcinated at 7500C for 12 hours in powder form. The samples were then palletized and sintered at 8000C for 24 hours with intermediate grindings. Break the pellet and regrind it. Then repelletized it and put in the furnace for heating at 810 oC for 36 hrs. Typical flow chart showing the sample preparation is displayed in Fig. 1. The samples were characterized for phase purity and lattice constants by room temperature X-ray diffraction (Philips, PANalytic). Superconducting properties were examined by four-probe van der Pauw geometry using a cryostat.
Fig. 2: X-ray diffractogram of (Bi1.65Pb0.35 )2Sr2Ca2Cu3O10+δ high Tc superconductor.
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