Phonon anomalies and local atomic displacements in the exchange-enhanced superconductor U/sub 6/Fe

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.32.4419· OSTI ID:5266228

Kimball, C W; Vaishnava, P P; Dwight, A E; Jorgensen, J D; Fradin, F Y

Moessbauer effect and neutron-diffraction measurements have been made as a function of temperature on the exchange-enhanced superconductor U/sub 6/Fe. Non-Debye behavior is observed in the thermal mean-squared displacement of Fe with the Debye temperature changing from THETA/sub f/approx. =320 K above 100 K to THETA/sub f/approx. =400 K below 80 K. Changes in the Moessbauer shift below 100 K are attributed principally to electronic-structure changes of the Fe atom which lead to a small increase in the number of d electrons and a concomitant reduction in the number of s electrons. The neutron-diffraction results indicate a pronounced anisotropy in the unit-cell thermal expansion and below 100 K an anomalous temperature dependence for the c-axis component of the total Debye-Waller factor of Fe. These observations taken together imply that along the c axis, static displacements of the Fe atoms begin around 100 K and increase with decreasing temperature.

• Research Organization: Northern Illinois University, DeKalb, Illinois 60115
• OSTI ID: 5266228
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 32:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDE ALLOYS
ALLOYS
COHERENT SCATTERING
DATA
DEBYE-WALLER FACTOR
DIFFRACTION
DISTANCE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC SPECIFIC HEAT
EXCHANGE INTERACTIONS
EXPERIMENTAL DATA
INFORMATION
INTERACTIONS
INTERATOMIC DISTANCES
IRON ALLOYS
LOW TEMPERATURE
MOESSBAUER EFFECT
NEUTRON DIFFRACTION
NUMERICAL DATA
PHONONS
PHYSICAL PROPERTIES
QUASI PARTICLES
SCATTERING
SPECIFIC HEAT
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
URANIUM ALLOYS