Kondo-like effect in antiferromagnetic gamma -Fe-Mn-Ge alloys at low temperature
Zhang Yangsheng; Zhang Yangsheng; Dept. of Mater. Sci. & Eng., Dalian Railway Inst., China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1995-05-08
Аннотация:
The temperature T dependence of the magnetic susceptibility chi and electrical resistivity rho of gamma -Fe-31 at.% Mn alloys containing 2-8.7 at.% Ge and 5.2 at.% Cr were measured in detail over the temperature range 5-500 K. The Neel transition of these alloys accompanied by an anomalous change in rho has been observed at a temperature of 300-430 K. In lowering the temperature to about 5 K, no second resistivity anomaly for gamma -Fe-31 at.% Mn or gamma -Fe-31 at.% Mn-5.2 at.% Cr alloys was found, but a secondary resistivity minimum was observed below 50 K in the gamma -Fe-31 at.% Mn-Ge alloys. The resistivity minimum temperature T<sub>min</sub> increases in proportion to the Ge concentration, and the resistivity measured from T<sub>min</sub> to about 5 K of the Fe-Mn-Ge alloys can be plotted as a linear function of log T, T<sup>2</sup> and square root T. These results suggest that the resistivity minimum in antiferromagnetic gamma -Fe-Mn-Ge alloys is due to a Kondo-like effect caused by localized magnetic moments on Fe atom sites which are induced or enhanced by the solution of Ge in gamma -Fe-Mn alloys.
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