Intrinsic paramagnetic centers in 1-2-3 supeconductors
- Kazan State Univ. (Russian Federation); and others
The {sup 169}Tm {open_quotes}enhanced{close_quotes} NMR in TmBa{sub 2}Cu{sub 3}O{sub 6+x} (x=0.5, 0.6) at temperatures below 4.2K and the {sup 63}Cu(1) NQR in YBa{sub 2}Cu{sub 3}O{sub 6.5} at temperatures above 4.2K are used to study properties of intrinsic paramagnetic centers incorporated into superconducting materials. The spin-lattice relaxation of thulium and copper nuclei reveals three types of paramagnetic centers to be present in oxygen-deficient 1-2-3 superconductors, those are (1) two-level ones with a spin S=1/2, localized outside CuO{sub 2} bilayers, (2) singlet-ground-state paramagnetic centers with an integer spin S{ge}1 in CuO{sub 2} bilayers, and (3) exchange copper-oxygen clusters with a half-integer spin S{ge}5/2, localized in a nearest neighborhood of CuO{sub x} basal plane at boundaries of superconducting Ortho II microdomains.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 136182
- Report Number(s):
- CONF-950144--; CNN: Project 91001; Grant HTECH 930343
- Journal Information:
- Journal of Superconductivity, Journal Name: Journal of Superconductivity Journal Issue: 4 Vol. 8; ISSN JOUSEH; ISSN 0896-1107
- Country of Publication:
- United States
- Language:
- English
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