Abstract
(Tl0.5Pb0.5)(Ba0.2 Sr0.8)2Ca2Cu3Oy (Tl,Pb-1223) has been prepared, characterized and oriented for NMR studies. For comparison, we also fabricated (Tl0.5Pb0.5)(Ba0.1 Sr0.9)2CaCu2Oy (Tl,Pb-1212). In the case of (Tl0.5Pb0.5)(Ba0.2 Sr0.8)2Ca2Cu3Oy the 205Tl NMR spectra and the spin-lattice relaxation time were measured in the temperature range from 68 to 300 K. For (Tl0.5Pb0.5)(Ba0.1 Sr0.9)2CaCu2Oy the 205Tl spectra were measured at room temperature only. The 207Pb NMR spectra for both compounds were also obtained at room temperature. From the chemical shift measurements it was concluded that the valence states of Tl and Pb were 3+ and 4+, respectively. In addition, a linear relationship was found between the shift and the critical temperatures. At low temperatures an anisotropic melting of the vortex state was observed.
Original language | English |
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Pages (from-to) | 129-140 |
Number of pages | 12 |
Journal | Physica C: Superconductivity and its Applications |
Volume | 356 |
Issue number | 1-2 |
DOIs | |
State | Published - 7 Jan 2001 |
Keywords
- (Tl,Pb-1223) superconductors
- Pb NMR spectroscopy
- Tl NMR spectroscopy
- Vortex states
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering