ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Although the annealed equiatomic alloy FeAl is paramagnetic, the series of alloys represented by the formula FeAl1−xCux becomes ferromagnetic for x≥0.27, beyond which the Curie temperature rises rapidly. It is thought that the magnetization in high fields arises from saturated clusters in an itinerant matrix. Five of these alloys (having x=0.25, 0.28, 0.30, 0.325, and 0.35) have been examined in powder form over the range 4–300 K using SANS at ILL, Grenoble. The paramagnetic alloy with x=0.25 shows a featureless, temperature-independent scattering pattern with some forward peaking which may arise primarily from surface scattering. In contrast, the results for the ferromagnetic alloys show marked features which can be linked to the magnetic properties; that for the alloy with x=0.325 is especially remarkable in that very weak critical scattering is seen near the Curie temperature with a much larger Q-dependent peak at about 50 K. These features are very similar in form to those reported for the alloy Fe70Al30 in which the ferromagnetism is thought to be broken up at low temperatures by random fields arising from dynamic magnetic clusters, leading to a reentrant (super)paramagnetism that freezes at lower temperatures into a cluster glass state. The correspondence between the two systems seems substantial.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.346032
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