Fermi surface of CeCu{sub 2}Si{sub 2} by 2D angular correlation of positron annihilation radiation
- Department of Physics, University of Geneva, 24 Quai E. Ansermet, CH-1211 Geneva 4 (Switzerland)
- Laboratory of Physics, Helsinki University of Technology, 02150 Espoo (Finland)
- Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- Institut fuer Festkoerperphysik, TH Darmstadt, SFB 252, D-64289 Darmstadt (Germany)
We have carried out 2D angular correlation of positron annihilation radiation measurements on oriented single crystals of the heavy-fermion superconductor CeCu{sub 2}Si{sub 2}. Measurements have been made at 50 and 4 K which are above and below the Kondo temperature, T{sub K}{approximately}15 K, for this compound. The measurements show a small temperature dependence. Experimental results have been compared with linear muffin-tin orbital band-structure calculations for CeCu{sub 2}Si{sub 2} and the isostructural non-f-electron compound, LaCu{sub 2}Si{sub 2}. The measured anisotropies agree well with the calculations. In addition, at both temperatures, the measured [001] projected k-space occupation densities reflect clearly the Fermi-surface breaks predicted by the calculations for CeCu{sub 2}Si{sub 2}. This implies that local-density approximation calculations provide a good description of the electronic structure in CeCu{sub 2}Si{sub 2}. We have also measured the positron lifetime in both superconducting (S-type) and magnetic (A-type) samples of CeCu{sub 2}Si{sub 2}. The lifetime and intensity components in the S- and A-type polycrystals are different, suggesting that the nature of the defects that trap positrons is different in the two phases. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 496741
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-pressure valence instability and T/sub c/ maximum in superconducting CeCu/sub 2/Si/sub 2/
Magnetoresistance of CeCu{sub 2}Si{sub 2}: Differences and similarities to UBe{sub 13}