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Published on: September 4, 2015
Fluctuating magnetic moments in liquid metals
Mark Patty1, Keary Schoen, Wouter Montfrooij
1Department of Physics and Astronomy, and Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211, USA.
Summary
Liquid metals exhibit an unexpected magnetic property. Neutron scattering reveals fluctuating magnetic moments in elements like mercury and aluminum, occurring at the same speed as atomic motion.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Physical Chemistry
Background:
- Neutron scattering is a key technique for probing atomic and magnetic dynamics in materials.
- Standard models of neutron scattering in liquid metals consider only coherent and incoherent processes.
- Previous analyses of liquid metal dynamics have not identified specific magnetic phenomena.
Purpose of the Study:
- To reanalyze existing neutron scattering data for liquid metals.
- To identify discrepancies between neutron scattering and x-ray scattering observations.
- To investigate the origin of an uncharacterized quasielastic neutron scattering mode.
Main Methods:
- Reanalysis of literature data on neutron scattering experiments on liquid metals.
- Comparison of neutron scattering results with complementary x-ray scattering data.
- Theoretical interpretation of observed scattering patterns using established physics principles.
Main Results:
- An additional, broad quasielastic neutron scattering mode was identified, absent in x-ray scattering.
- This mode cannot be explained by standard coherent and incoherent scattering mechanisms.
- The findings suggest the presence of fluctuating magnetic moments in nonmagnetic liquid metals.
Conclusions:
- Nonmagnetic liquid metals possess magnetic moments that fluctuate on a picosecond timescale.
- This magnetic fluctuation timescale matches the cage-diffusion process observed in liquid metals.
- Such fluctuating magnetic moments were detected in liquid mercury, aluminum, gallium, and lead.
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