Positron annihilation studies of organic superconductivity
- Missouri Univ., Kansas City, MO (United States); and others
The positron lifetimes of two organic superconductors, {kappa}-(ET){sub 2}Cu(NCS){sub 2} and {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Br, are measured as a function of temperature across {Tc}. A drop of positron lifetime below {Tc} is observed. Positron-electron momentum densities are measured by using 2D-ACAR to search for the Fermi surface in {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Br. Positron density distributions and positron-electron overlaps are calculated by using the orthogonalized linear combination atomic orbital (OLCAO) method to interprete the temperature dependence due to the local charge transfer which is inferred to relate to the superconducting transition. 2D-ACAR results in {kappa}-(ET){sub 2}Cu[N(CN){sub 2}]Br are compared with theoretical band calculations based on a first-principles local density approximation. Importance of performing accurate band calculations for the interpretation of positron annihilation data is emphasized.
- Research Organization:
- Argonne National Lab., IL (United States); Missouri Univ., Kansas City, MO (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); Department of the Air Force, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38; FG02-84ER45170
- OSTI ID:
- 10180039
- Report Number(s):
- ANL/CHM/CP-83942; CONF-9405170-7; ON: DE94018371; BR: ER0000000/KC0201010; TRN: 94:018900
- Resource Relation:
- Conference: 10. international conference on positron annihilation,Beijing (China),23-29 May 1994; Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
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