Magnetic Ordering in Gold-Iron Alloys
Abstract
In an attempt to characterize the magnetic ordering in AuFe alloys, systematic studies were made of the temperature dependences of the thermoelectric power S and the low-field magnetic susceptibility χ for Fe concentrations C from 1 to 22 at.%. The concentration dependences of the magnitude and temperature of the maximum in S(T) showed transitions clearly related to the magnetic ordering. Data analyses based on molecular field theories indicate the existence of small regions of short-range ferromagnetic order which undergo longrange interactions as the temperature is lowered. For C>~12 at.%, long-range ferromagnetism is dominant. Lower-concentration alloys (C<~12 at.%) exhibit an antiferromagnetism with some properties similar to those of a magnetic spin-glass, but with well-defined ordering temperatures characterized by sharp cusps in χ(T), and with a negative Curie θ for C=1 and 2 at.%. These properties indicate a more perfect antiferromagnetic order than that expected for a random alloy or a spin-glass, and this may be related to preferred local lattice arrangements in these alloys.
- Publication:
-
Physical Review B
- Pub Date:
- December 1972
- DOI:
- 10.1103/PhysRevB.6.4220
- Bibcode:
- 1972PhRvB...6.4220C