Crystalline electric fields in mixed valent systems (invited)

Journal Article · Sun Mar 01 04:00:00 EST 1981 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.328854· OSTI ID:5725516

Shapiro, S M

The inelastic neutron studies of rare-earth-based mixed valent systems have all shown remarkably similar results: a broad quasielastic line with half width on the order of 10 meV. This width exhibits a strong temperature dependence in those systems which undergo a valence transition and is only weakly temperature dependent in those systems which show no transition. A surprising result was the absence of crystalline electric field (CEF) excitations. Recent measurements on the alloy Ce/sub .9-x/La/sub x/Th/sub .1/ have revealed the existence of CEF excitations. For x = 0, the valence transition is strongly first order and occurs near T/sub o/approx. =150 K. The inelastic spectra exhibit the typical broad quasielastic scattering. As x increases, T/sub o/ decreases, due to internal pressure effects, and a well-defined, but broad, excitation appears near E = 15 meV. This is interpreted as a CEF excitation between the GAMMA/sub 7/ and GAMMA/sub 8/ levels of the Ce/sup 3 +/ ion. For x = 0.40, the valence transition is almost completely suppressed and the excitation becomes even sharper.

• Research Organization: Brookhaven National Laboratory, Upton, New York 11973
• OSTI ID: 5725516
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 52:3; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL FIELD
CRYSTALS
DIFFRACTION
ELECTRONIC STRUCTURE
ENERGY-LEVEL TRANSITIONS
INELASTIC SCATTERING
MAGNETIC PROPERTIES
NEUTRON DIFFRACTION
PHYSICAL PROPERTIES
POLYCRYSTALS
PRESSURE DEPENDENCE
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SAMARIUM SULFIDES
SCATTERING
SPECTRA
SULFIDES
SULFUR COMPOUNDS
TEMPERATURE DEPENDENCE
VALENCE