Neutron-scattering investigation of the phonons in intermediate-valence Sm/sub 0. 75/Y/sub 0. 25/S

Journal Article · Wed Aug 15 04:00:00 EDT 1979 · Phys. Rev., B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.20.1656· OSTI ID:6012241

Mook, H A; Nicklow, R M

Neutron-scattering techniques have been used to measure the phonons in intermediate-valence Sm/sub 0.75/Y/sub 0.25/S. Anomalies are found in the shape of the phonon dispersion curves and in the phonon widths that are attributable to mixed-valence effects. Phonon positions and widths are shown as a function of temperature. The greatest phonon softening and the largest phonon widths are found at the valence transition that occurs at 200 K. A screened-rigid-ion model has been used to fit the phonon dispersion curves. The model reproduces the general shape of the phonon dispersion data but fails to account for the anomalies.

• Research Organization: Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• OSTI ID: 6012241
• Journal Information: Phys. Rev., B: Condens. Matter; (United States), Journal Name: Phys. Rev., B: Condens. Matter; (United States) Vol. 20:4; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DISPERSION RELATIONS
LINE WIDTHS
NEUTRON DIFFRACTION
PHONONS
PHYSICAL PROPERTIES
QUASI PARTICLES
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SAMARIUM SULFIDES
SCATTERING
SULFIDES
SULFUR COMPOUNDS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VALENCE
YTTRIUM COMPOUNDS
YTTRIUM SULFIDES