Electron spin resonance and magnetic susceptibility suggest superconductivity in Na doped WO3samples |
| |
Authors: | A. Shengelaya S. Reich Y. Tsabba K.A. Müller |
| |
Affiliation: | Physik-Institut der Universit?t Zürich, 8057, Zürich, Switzerland Department of Materials and Interfaces, The Weizmann Institute of Science, 76100, Rehovot, Israel
|
| |
Abstract: | In WO3 doped with Na (WO3:Na) an Electron Spin Resonance (ESR) signal with unresolved fine and/or hyperfine structure is detected and used as a probe for the state of the carriers. Using the saturation method we determined the spin-lattice relaxation rate 1/ T 1 of these paramagnetic centers. Upon cooling below 100 K, 1/ T 1 decreases markedly, as known to occur in NMR when a gap opens in the superconducting state. At low temperatures, 1/ T 1 quantitatively follows BCS behavior with a gap K or 2 . The magnetic susceptibility exhibits a strong difference between magnetic-field cooled and zero-field cooled regimes below which also supports a so far unknown superconducting phase resulting from Na doping. Received 14 April 1999 and Received in final form 6 September 1999 |
| |
Keywords: | PACS. 74.72.-h High-Tc compounds - 76.30.-v Electron paramagnetic resonance and relaxation |
本文献已被 SpringerLink 等数据库收录! |
|