Processing of Bi–Sr–Ca–Cu–O glasses using platinum and alumina crucibles
نویسندگان
چکیده
Reactions with alumina and platinum crucibles were studied during the preparation of Bi2Sr2Ca1Cu2Oy “2212” glasses. In particular, reactions with Al2O3 are of interest since alumina is a potential substrate material in applications of this superconductor. Glasses processed using alumina crucibles were completely homogeneous and free of secondary phases although the material contained 2.26 at. % Al in solution. After heat treatments, Al was found in the form of SrCaAlOy particles located primarily along grain boundaries of the 2212 superconducting phase. Platinum contamination was minimal (14−xCaxCu24O41, and 2201 as second phases. Differential thermal analysis (DTA) suggested that the crystallization processes were essentially the same for all samples although the small amount of Al seemed to slow the kinetics leading to the formation of 2212. Neither Al nor Pt was detected within the 2212 phase. The measured superconducting compositions in each annealed sample were nearly the same with identical transition temperatures of 88 K. Overall differences in stoichiometry were accommodated by changes in the number and composition of the secondary phases present.
منابع مشابه
Conductivity and Superconductivity of (Bi,Pb)4Sr3Ca3Cu4Ox Glass-Ceramics
(Bi,Pb)–Sr−Ca–Cu–O glasses, annealed in proper conditions, transform into a granular metal and superconductor. As a result of annealing oxide superconductors belonging to the bismuth family (Bi,Pb)2Sr2CuOx, (Bi,Pb)2Sr2CaCu2Ox, and (Bi,Pb)2Sr2Ca2Cu3Ox crystallize. (Bi,Pb)–Sr– Ca–Cu–O glass-ceramic samples were obtained by annealing the amorphous solid at temperatures between 500◦C and 870◦C. The...
متن کاملخواص مغناطیسی و ساختاری ابررسانای 2223- Bi آلاییده با کادمیوم
In this paper, Bi1.64-xPb0.36CdxSr2Ca2Cu3Oy (BPCSCCO) superconductor with x = 0.0, 0.02, 0.04 and 0.06 is made by the solid state reaction method. The magnetic susceptibility measurements were performed using AC susceptometer. The microstructure and morphology of the samples have been studied by X-ray diffraction, scanning electron microscope and energy dispersive X-ray. The results show that t...
متن کاملPrimary Phase Field of the Pb-Doped 2223 High-Tc Superconductor in the (Bi, Pb)-Sr-Ca-Cu-O System
Both liquidus and subsolidus phase equilibrium data are of central importance for applications of high temperature supercon-ductors in the (Bi, Pb)-Sr-Ca-Cu-O system, including material synthesis, melt processing and single crystal growth. The sub-solidus equilibria of the 110 K high-Tc Pb-doped 2223 ([Bi, Pb], Sr, Ca, Cu) phase and the location of the primary phase field (crystallization field...
متن کاملابررسانای پایه بیسموت
In this paper, Bi-Sr-Ca-Cu-O (BCSCCO) system superconductor is made by the solid state reaction method. The effect of doping Pb, Cd, Sb, Cu and annealing time on the critical temperature and critical current density have been investigated. The microstructure and morphology of the samples have been studied by X-ray diffraction, scanning electron microscope and energy dispersive X-ray. The resu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2017