ISSN:
1432-0630
Keywords:
PACS: 72.20; 81.40
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract. A method has been developed for determining the effective concentration of shallow impurities N * responsible for the low-temperature conductivity in the vicinity of the metal–insulator transition for inhomo-geneous samples of n-Ge : As. The method is based on the measurement of two ratios of sample resistance γ=R(4.2 K)/R(300 K), β=R(2.0 K)/R(4.2 K) and the conductivity σ(4.2 K) . The next step consists of plotting γ and σ(4.2) vs β. Assuming that β is the most reliable parameter, one can calculate, after an averaging procedure, the corrected values of γ*, σ*(4.2) and the resistivity at room temperature ρ*(300)=[γ*σ*(4.2)]-1. Finally, using the known dependence ρ(300)=f (N) for homogeneous samples, one can obtain the values of N *. The dependences of N * on β and on γ are plotted. The scaling behavior of the conductivity of the Ge : As samples with corrected values of σ*(4.2) and N * has been observed down to T=100 mK.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003390050176
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