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in creator/contributor: "Zhong, W."

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Melt-processing of Y-Ba-Cu-O superconductors for improved levitation

Melt processed bulk YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) superconductors are of considerable interest in the application of low-friction, superconducting permanent magnet bearings and flywheel-energy-storage devices. The mechanisms of enhanced flux pinning in the melt processed samples has been the subject of many investigations. Fine precipitates of Y{sub 2}BaCuO{sub 5} (211) are considered potential flux-pinning sites by many investigators. Several groups have reported the refinem… more

Date: April 1, 1994

Creator: Balachandran, U.; Zhong, W.; Emerson, J. E. & McDaniel, R. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Microstructure and associated properties of YBa{sub 2}Cu{sub 3}O{sub x} superconductors prepared by melt-processing techniques

From the standpoint of applications, melt-processed bulk YBa{sub 2}Cu{sub 3}O{sub x} (YBCO) superconductors are of considerable interest. We have studied the microstructure and levitation force of melt-processed YBCO, YBCO plus Y{sub 2}BaCuO{sub 5}, and YBCO plus Pt samples. Large single crystalline samples, grown using a seeding technique, were also studied. The levitation force is highest in melt-processed samples made by the seeding technique. 6 figs, 24 refs.

Date: March 1993

Creator: Balachandran, U.; Zhong, W.; Youngdahl, C. A. & Poeppel, R. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Microstructure and Associated Properties of YBa[sub 2]Cu[sub 3]O[sub x] Superconductors Prepared by Melt-Processing Techniques

From the standpoint of applications, melt-processed bulk YBa[sub 2]Cu[sub 3]O[sub x] (YBCO) superconductors are of considerable interest. We have studied the microstructure and levitation force of melt-processed YBCO, YBCO plus Y[sub 2]BaCuO[sub 5], and YBCO plus Pt samples. Large single crystalline samples, grown using a seeding technique, were also studied. The levitation force is highest in melt-processed samples made by the seeding technique. 6 figs, 24 refs.

Date: March 1, 1993

Creator: Balachandran, U.; Zhong, W.; Youngdahl, C. A. & Poeppel, R. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Processing of YBCO superconductors for improved levitation force

One objective of the ANL superconductor program is to develop improved processing methods for production of YBCO superconductors with higher levitation forces suitable for low-friction, superconductor/permanent-magnet bearings and flywheel-energy-storage applications. From the standpoint of these applications, melt-processed bulk YBCO superconductors are of considerable interest. Levitation force and flux-pinning properties depend on microstructural features of the superconductors. We have adde… more

Date: May 1, 1993

Creator: Balachandran, U. & Zhong, W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effect of lead content on phase evolution and microstructural development in Ag-clad Bi-2223 composite conductors

A two powder process was used to prepare silver-sheathed monofilamentary Bi{sub 1.8}Pb{sub x}Sr{sub 1.98}Ca{sub 1.97}Cu{sub 3.08}O{sub y} (Bi-2223) tapes with varying lead contents, x, from 0.2 to 0.5. The resulting tapes were subjected to thermomechanical processing and then characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray analysis (EDX). Layered phase texture was accessed using image analysis software on scanned SEM micrographs. Transpo… more

Date: February 1, 1997

Creator: Merchant, N. N.; Maroni, V. A.; Fischer, A. K.; Dorris, S. E.; Zhong, W. & Ashcom, N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Magneto-optical imaging of transport current densities in superconductors

Direct imaging of the paths of transport currents in superconductors creates many new possibilities for exploring the basic features of vortex pinning mechanisms and for improving the performance of superconducting materials. A technique for imaging the path and magnitude of the transport current density flowing in superconductors is described. Results are given for a 37-filament BSCCO 2223 powder-in-tube wire, showing a highly inhomogeneous current path within the filaments.

Date: December 31, 1995

Creator: Crabtree, G. W.; Welp, U.; Gunter, D. O.; Zhong, W.; Balachandran, U.; Haldar, P. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department