Stability of the Surface Spin Flop Transition in a Finite Uniaxial Antiferromagnetic Superlattice
Abstract
In a magnetic field, a finite uniaxial antiferromagnet (AF) undergoes a surface spin flop (SSF) transition, where an AF domain wall nucleates at the surface. The SSF transition, like the bulk spin flop (BSF) transition in bulk AF, is a first-order phase transition when the field is exactly along the easy axis. The BSF transition remains first order when the field direction is within a critical angle from the easy axis. Using a uniaxial antiferromagnetically exchange-coupled Fe/Cr superlattice as a model finite AF, we have investigated the stability of the SSF transition when the applied field direction is askew from the easy axis. Magnetization and magnetoresistance measurements show that the SSF is stable up to a critical skew angle twice as large as that for the BSF transition. The SSF transition field increases with the skew angle at low temperature, but decreases with the skew angle at room temperature. The experimental observations are compared with numerical simulations.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARN26011J