Abstract
Bulk superconducting samples of HgBa2CuO4+δ (hereafter denoted as Hg-1201) were prepared by solid state reaction of stoichiometric quantities of HgO and Ba2CuO3 precursors. The "as-synthesized" Hg-1201 samples had a Tc of 95 K, as defined by the onset of diamagnetism. The crystal symmetry was found to be tetragonal with lattice parameters, a=3.876(2) A ̊, and c=9.515(3) A ̊, similar to the literature values. Finely ground X-ray specimens were stable upon exposure to ambient air for a period of ≁24 h. Magnetic characterizations were conducted using a SQUID based DC magnetometer. Studies of the transition region in low applied fields showed complete screening and evidence for weak intergrain coupling of the randomly oriented crystallites. High field magnetic hysteresis studies showed rapid decay of hysteresis of the magnetization (proportional to the current density), both with applied field and temperature. These findings are attributed to the presence of substantial thermally activated flux motion.
Original language | English |
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Pages (from-to) | 271-275 |
Number of pages | 5 |
Journal | Physica C: Superconductivity and its Applications |
Volume | 213 |
Issue number | 3-4 |
DOIs | |
State | Published - Aug 15 1993 |
Funding
The research was sponsored by the Division of Materials Sciences, Office of Basic Energy Sciences, US. Department of Energy and technology development was funded by the US Department of Energy Office of Advanced Utility Concept-Superconductor Technology Program, both under contract DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc. A portion of the work of JRT and YRS was supported by the Science Alliance at The University of Tennessee, Knoxville and work of MP was supported by the Oak Ridge National Laboratory, Postdoctoral Research Program, administered jointly by the Oak Ridge Institute for Science and Education and ORNL.
Funders | Funder number |
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Office of Basic Energy Sciences | |
US Department of Energy Office of Advanced Utility Concept-Superconductor Technology Program | DE-AC05-84OR21400 |
Oak Ridge National Laboratory | |
Oak Ridge Institute for Science and Education | |
University of Tennessee | |
Division of Materials Sciences and Engineering |