Superconductivity in Dense MgB{sub 2} Wires
MgB{sub 2} becomes superconducting just below 40K. Whereas porous polycrystalline samples of MgB{sub 2} can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB{sub 2} can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 {mu}m , are better than 80% dense, and manifest the full {chi}=-1/4{pi} shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB{sub 2} is a highly conducting metal in the normal state with {rho}(40 K)=0.38 {mu}{Omega}cm . By using this value, an electronic mean-free path, l{approx}600 {angstrom} can be estimated, indicating that MgB{sub 2} wires are well within the clean limit. T{sub c} , H{sub c2}(T) , and J{sub c} data indicate that MgB{sub 2} manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40205714
- Journal Information:
- Physical Review Letters, Vol. 86, Issue 11; Other Information: DOI: 10.1103/PhysRevLett.86.2423; Othernumber: PRLTAO000086000011002423000001; 054113PRL; PBD: 12 Mar 2001; ISSN 0031-9007
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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