ISSN:
1434-601X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The electrical resistivity of dilute Zn-Mn alloys (c=0–0.6 at% Mn) has been measured in a temperature range from room temperature (RT) down to 0.4 °K. Three different series of samples are investigated: 1. annealed 72 h, 400 °C, 2. annealed and aged 1 year atRT, 3. coldworked atRT. All samples show a minimum in the residual resistance atT min∝c 1/5 followed by an increase of the resistivityρ∝k s · lnT (Kondo-effect). For some alloys the resistivity minimum is followed by a resistivity maximum atT max.T max mainly depends on the distribution of the Mnatoms in the Zn-matrix. The coefficientk s is also strongly influenced by changes of the Mn-distribution. For alloys withc〉0.02 at% (max. solubility of Mn in Zn atRT) the slopek s =∂ρ/∂ lnT decreases with increasing degree of precipitation of the manganese. Samples withc〈0.02 at% however, show the opposite effect, increasingk s with increasing Mn-precipitation. Moreover, during the aging process, we observe an increase in the “residual resistance” (resistance ratioR T/R 293 atT min) for these alloys. The effect can be explained by assuming that the precipitation leads to the formation of superparamagnetic clusters.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01394721
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