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Domain-wall spin dynamics in kagome antiferromagnets
E Lhotel1, V Simonet, J Ortloff
1Institut Néel, CNRS & Université Joseph Fourier, BP 166, 38042 Grenoble Cedex 9, France. elsa.lhotel@grenoble.cnrs.fr
Physical Review Letters
|January 17, 2012
Summary
New iron-based kagome antiferromagnets exhibit unusual slow spin dynamics due to domain walls. These dynamics evolve with decreasing temperature, likely influenced by dipolar interactions and forming independent magnetic grains.
Area of Science:
- Condensed Matter Physics
- Magnetism
- Materials Science
Background:
- Frustrated magnets, such as kagome antiferromagnets, display complex magnetic behaviors due to competing interactions.
- Iron-based kagome systems are of interest for their potential unique magnetic properties.
Purpose of the Study:
- To investigate the magnetic properties and spin dynamics of a new family of iron-based kagome antiferromagnets.
- To understand the influence of local spin anisotropy and network connectivity on magnetic ordering.
Main Methods:
- Magnetization measurements down to 60 mK.
- Neutron scattering experiments to probe spin dynamics.
Main Results:
- Observed slow spin dynamics in the ordered phase, attributed to domain walls intersecting kagome planes via free spins.
- Spin dynamics evolved from exchange-released spin flips to cooperative behavior with decreasing temperature.
- Evidence of long-range dipolar interaction onset influencing spin dynamics.
- Formation of a domain structure comprising independent magnetic grains.
Conclusions:
- The studied iron-based kagome antiferromagnets exhibit novel slow spin dynamics.
- The observed phenomena are linked to a combination of strong local spin anisotropy, low exchange connectivity, and dipolar interactions.
- The resulting domain structure of independent magnetic grains may be a general characteristic of frustrated magnets.
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