Electronic structures of narrow-band materials

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5060800

Kang, Jeongsoo

This thesis investigates the electronic structures of narrow-band actinide, rare earth, and transition metal materials, using the experimental techniques of photoemission (PES) and inverse photoemission (BIS) spectroscopy. Narrow-band materials exhibit many interesting phenomena such as mixed-valence, heavy-fermion properties, and high temperature superconductivity. This is primarily due to the correlated narrow band electrons and their interaction with conduction or valence band electrons. The theoretical characterization of the electronic structures of a many body system is the spectral weight of the single particle Green's function. The spectral weight of narrow band electrons is determined by measuring the PES/BIS spectrum, the spectrum to remove and add electrons. For Ce compounds, the impurity Anderson Hamiltonian can describe both the ground state properties and the 4f spectrum. In this description, the low-energy properties are determined by a low-energy scale set by the Kondo temperature, which characterizes spin fluctuations. To make a detailed test of this picture, the Ce 3d and 4f spectra are measured and analyzed using this model for Ce(Ru{sub 1{minus}x}Rh{sub x}){sub 3}B{sub 2} and CeCu{sub 2}Si{sub 2}. The spectral change during the {alpha}-{gamma} phase transition of Ce{sub 0.7}Th{sub 0.3} has been analyzed. The Yb 4f spectrum of YbAl{sub 3} is measured and analyzed by applying the impurity Anderson Hamiltonian calculations for Ce to Yb with an electron-hole mapping. The author has studied the 4f spectra of heavy-fermion compounds, YbXCu{sub 4}, with X = Ag, Au, and Pd. The 5f spectra of uranium materials do not resemble the Ce 4f spectra, in having much more f-weight around E{sub F}. However, the measured 5f width of the heavy fermion uranium materials exceeds the 5f width obtained from the local density functional calculations.

• Research Organization: California Univ., San Diego, CA (United States)
• OSTI ID: 5060800
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDE ALLOYS
ACTINIDES
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
BARIUM COMPOUNDS
BARIUM OXIDES
CERIUM ALLOYS
CERIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CORRELATIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
EMISSION
FERMIONS
FUNCTIONS
GREEN FUNCTION
HIGH-TC SUPERCONDUCTORS
INTERMETALLIC COMPOUNDS
KONDO EFFECT
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LEPTONS
MANY-BODY PROBLEM
METALS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM ALLOYS
PHASE TRANSFORMATIONS
PHOTOEMISSION
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RARE EARTH ALLOYS
RARE EARTH COMPOUNDS
RARE EARTHS
RUTHENIUM ALLOYS
SECONDARY EMISSION
SILICON ALLOYS
SPECTRA
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
URANIUM ALLOYS
YTTERBIUM ALLOYS
YTTRIUM ALLOYS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES