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Effective One-Dimensional Coupling in the Highly Frustrated Square-Lattice Itinerant Magnet CaCo_{2-y}As_{2}
A Sapkota1,2, B G Ueland1,2, V K Anand1,3
1Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011, USA.
Physical Review Letters
|October 21, 2017
Summary
Measurements reveal one-dimensional spin interactions in CaCo_{2-y}As_{2} due to bond frustration. This finding suggests expanding studies of the J1-J2 Heisenberg model to include itinerant spin systems.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Magnetism
Background:
- CaCo_{2-y}As_{2} is an itinerant antiferromagnet.
- The J1-J2 Heisenberg model describes spin interactions on a square lattice.
Purpose of the Study:
- Investigate spin interactions in CaCo_{2-y}As_{2} using inelastic neutron scattering.
- Determine the nature of magnetic interactions in this itinerant system.
Main Methods:
- Inelastic neutron scattering measurements were performed at 8 K.
- Analysis focused on reciprocal space scattering patterns perpendicular to the Co square lattice.
Main Results:
- Observed two orthogonal planes of scattering perpendicular to the Co square lattice.
- Demonstrated the presence of effective one-dimensional spin interactions.
- Attributed these interactions to near-perfect bond frustration in the J1-J2 Heisenberg model with ferromagnetic J1.
Conclusions:
- The J1-J2 Heisenberg model with ferromagnetic J1 accurately describes the observed spin dynamics.
- Experimental and theoretical studies of the J1-J2 Heisenberg model should incorporate itinerant spin systems, not just local-moment ones.
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