Spin dynamics in the mixed valence alloy Ce/sub 1ts-tsx/Th/sub x/

Journal Article · Thu Sep 01 04:00:00 EDT 1977 · Phys. Rev., B; (United States)

DOI:https://doi.org/10.1103/PhysRevB.16.2225· OSTI ID:7215100

Shapiro, S M; Axe, J D; Birgeneau, R J; Lawrence, J M; Parks, R D

Temperature-dependent neutron-scattering experiments have been performed on a polycrystalline sample of Ce/sub 0.74/Th/sub 0.26/ which undergoes a first-order ..gamma..-..cap alpha.. valence transition at T/sub V/ approx. 150 K. By a measurement of the temperature dependence of the lattice parameter and use of Vegard's law, we estimate the temperature behavior of the valence of Ce. The Q dependence of the magnetic scattering is found to follow the form factor of the Ce/sup 3 +/ ion surprisingly well. In the inelastic scans particular attention has been paid to the subtraction of the phonon background via an inelastic study of an identically sized and shaped sample of the nonmagnetic material La/sub 0.73/Th/sub 0.27/. The corrected Ce/sub 0.74/Th/sub 0.26/ spectra have then been expressed in the form of the imaginary part of the susceptibility chi'' (Q, ..omega..). The ..gamma..-phase dynamic susceptibility is a broad feature with significant intensity extending beyond 70.0 meV (the limit of our measurement) with a peak near approx.20.0 meV. On cooling below T/sub V/ the susceptibility decreases in magnitude and broadens such that the peak is beyond 70.0 meV. These results are compared with the macroscopic magnetic susceptibility which exhibits behavior similar to chi (Q) obtained from chi'' (Q, ..omega..) by a Kramers-Kronig analysis.

• Research Organization: Brookhaven National Laboratory, Upton, New York 11973
• OSTI ID: 7215100
• Journal Information: Phys. Rev., B; (United States), Journal Name: Phys. Rev., B; (United States) Vol. 16:5; ISSN PLRBA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ACTINIDE ALLOYS
ALLOYS
CERIUM ALLOYS
COHERENT SCATTERING
CRYSTALS
DIFFRACTION
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
NEUTRON DIFFRACTION
ORDER PARAMETERS
PHYSICAL PROPERTIES
POLYCRYSTALS
RARE EARTH ALLOYS
SCATTERING
TEMPERATURE DEPENDENCE
THORIUM ALLOYS
VALENCE