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The spin dependent momentum density of hexagonal close packed cobalt
P K Lawson1, D N Timms, M A Dixon
1Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
Journal of X-Ray Science and Technology
|February 11, 2011
Summary
Spin-dependent Compton profiles of cobalt metal were measured using synchrotron radiation. Experiments revealed more 3d spin density at high momentum than predicted by augmented plane wave calculations.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum mechanics
Background:
- Ferromagnetic hexagonal close packed cobalt metal exhibits complex electronic properties.
- Understanding electron momentum density is crucial for characterizing magnetic materials.
Purpose of the Study:
- To measure directional-spin-dependent Compton profiles of cobalt metal.
- To compare experimental results with theoretical predictions from augmented plane wave (APW) calculations.
- To investigate discrepancies in electron momentum density and spin density.
Main Methods:
- Utilized circularly polarized synchrotron radiation at 117 keV and 167 keV.
- Employed a new ESRF high energy beamline for improved resolution.
- Analyzed directional-spin-dependent Compton profiles.
Main Results:
- Achieved significantly improved resolution at higher energy (167 keV).
- Observed no significant difference between c-axis and basal plane magnetic profiles.
- Found substantially more 3d spin density at high momentum than predicted by APW calculations.
- Identified remaining significant differences in the 4s-p component of momentum density after corrections.
Conclusions:
- Experimental Compton profiles provide valuable insights into the electronic structure of cobalt.
- The augmented plane wave model requires refinement to accurately capture high-momentum spin density.
- Further theoretical and experimental investigations are needed to fully understand the electron momentum density in ferromagnetic cobalt.
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