ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The electrical resistivity of diluteZnMn alloys (c=1.7–2400 ppm Mn) has been investigated in the temperature range from 0.05 to 14 K. For the most dilute sample, single-impurity Kondo behavior is found, well described by the Hamann formula withT K=0.9 K,S=3/2. ForT〈50 mK, aT 2 law with θ R =0.3 K is expected. In the dilute limit the Kondo slope is −(1/c)d(Δρ)/d(logT)=3.7±0.2 µΩ-cm/at % dec. In the more highly concentrated alloys, the slope decreases with increasing c and the lnT-like variation of the Kondo resistivity roughly terminates near a temperatureT W(c),T W being related to the average Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction strength between the Mn impurities. For 20 ppm ≤c ≤ 1000 ppm, the resistivity slightly decreases at low temperatures and a broad resistivity maximum is observed atT m (c), withT m ∝c 0.7. ForT 2〈T m, the resistivity dependence is linear inT, and for the most concentrated alloy aT 3/2 orT 2 dependence is measured at the lowest temperatures attainable. The investigation of the transition temperatureT c (c) to superconductivity ofZnMn results in a critical concentrationc cr=18 ppm Mn. The concentration dependence ofT c below 0.3 K suggests the presence of the Kondo effect, although impurity interactions may also influenceT c in this temperature range.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00661537
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