Band theoretic interpretation of neutron scattering experiments in metallic ferromagnets

Conference · Sun Jul 01 04:00:00 EDT 1979

OSTI ID:5998865

Cooke, J F

Magnetic excitations in the 3-d transition metal ferromagnets nickel and iron have been found to possess unusual properties not found in other magnetic systems. For example, inelastic neutron scattering experiments have revealed that spin-waves do not exist at wave-vectors above a particular cut-off value while below this cut-off point they have been observed well above the Curie temperature. This behavior is not consistent with predictions of localized spin models but can be explained by the band theoretic, or itinerant electron theory. In fact, first principles calculations of the low temperature neutron scattering cross-section based on the itinerant model have been shown to be in excellent agreement with experiment. In addition, the prediction of an optical spin-wave mode has been recently confirmed. The finite temperature extrapolation of the low temperature theory based on the traditional concept of a temperature-dependent spin-splitting of the electronic energy bands appears to be inconsistent with experiment. A more realistic first principles approach to develop a correct finite temperature theory is under investigation.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5998865
• Report Number(s): CONF-790877-3(Draft)
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BAND THEORY
COHERENT SCATTERING
CROSS SECTIONS
DATA
DATA FORMS
DIFFRACTION
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERROMAGNETIC MATERIALS
GRAPHS
INELASTIC SCATTERING
INFORMATION
MAGNETIC MATERIALS
MATERIALS
MATHEMATICAL MODELS
METALS
NEUTRON DIFFRACTION
NICKEL
NUMERICAL DATA
NUMERICAL SOLUTION
SCATTERING
SPIN WAVES
THEORETICAL DATA
TRANSITION ELEMENTS