Photoelectron Spectroscopy of YbInCu{sub 4}: Direct Testing of Correlated Electron Models

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:661894

Joyce, J J; Arko, A J; Sarrao, J L; Fisk, Z

The electronic properties of single crystal YbInCu{sub 4} have been investigated by means of high resolution photoelectron spectroscopy. A first order, isostructural phase transition for YbInCu{sub 4} at T{sub v}=42 K leads to changes in the Kondo temperature of more than an order of magnitude (27 K vs. 400 K). This phase transition and accompanying Kondo temperature change provide the most direct test of the single impurity model (SIM) to date. Particle hole symmetry allows the SIM to be used for Yb compounds as well as Ce heavy fermions with the great advantage that the predicted Kondo resonance is found on the occupied side of the spectral weight function for Yb materials and is thus directly observable in photoemission. The photoemission results are incongruous with the single impurity model predictions for temperature dependence, binding energy and 4f occupancy, encouraging a reevaluation of the single impurity model. The experiments were conducted using the PGM undulator and 4 meter NIM beamlines at SRC. The spectra were taken at photon energies of 40 eV and 90 eV and the combined energy resolution of the analyzer and monochromator was 45- 85 meV.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 661894
• Report Number(s): LA-UR--97-4211; CONF-9710154--; ON: DE98003006
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BINDING ENERGY
COPPER COMPOUNDS
ELECTRONIC STRUCTURE
INDIUM COMPOUNDS
PHOTOELECTRIC EMISSION
PHOTOELECTRON SPECTROSCOPY
YTTERBIUM COMPOUNDS