Direct observation of paramagnons in palladium
R Doubble1, S M Hayden, Pengcheng Dai
1H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom.
Physical Review Letters
|September 28, 2010
Summary
Inelastic neutron scattering reveals strong spin fluctuations in palladium, observed as collective magnetic excitations called paramagnons up to 128 meV. Despite their strength, rapid relaxation limits their impact on low-temperature heat capacity.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Magnetism
Background:
- Palladium is a nearly ferromagnetic element.
- Understanding spin fluctuations is crucial for predicting material properties.
Purpose of the Study:
- To investigate spin fluctuations in palladium using inelastic neutron scattering.
- To analyze the nature and energy of magnetic excitations.
- To estimate the contribution of spin fluctuations to heat capacity.
Main Methods:
- Inelastic neutron scattering (INS) experiments.
- Analysis using the Moriya-Lonzarich spin-fluctuation model.
Main Results:
- Observed dispersive, over-damped collective magnetic excitations (paramagnons) up to 128 meV.
- Paramagnon excitations are relatively strong but exhibit large relaxation rates.
- Estimated the contribution of spin fluctuations to low-temperature heat capacity.
Conclusions:
- Spin fluctuations in palladium are significant and extend to high energies.
- The large relaxation rates of paramagnons result in a minimal contribution to the electronic specific heat at low temperatures.
