Scaling analysis of the low temperature conductivity in neutron-transmutation-doped 70Ge:Ga

被引：0

作者：

Itoh, K.M. ^{[1
]}

Watanabe, M. ^{[1
]}

Ootuka, Y. ^{[2
]}

Haller, E.E. ^{[3
]}

机构：

[1] Dept. of Appl. Phys. and Phys.-Info., Keio University, Yokohama 223-8522, Japan

[2] Institute of Physics, University of Tsukuba, Ibaraki 305-8571, Japan

[3] UC Berkeley, Lawrence Berkeley Natl. Laboratory, Berkeley, CA 94720, United States

来源：

Annalen der Physik (Leipzig) | 1999年 / 8卷 / 07期

关键词：

Composition effects - Curve fitting - Electric conductivity - Nonlinear equations - Phase transitions - Semiconducting gallium - Semiconductor doping - Thermal effects;

D O I：

暂无

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学科分类号：

摘要：

We report on the scaling analysis of low temperature electron transport properties of nominally uncompensated neutron-transmutation-doped 70Ge:Ga samples in the critical regime for the metal-insulator transition. Ga concentration (N) and temperature (T) dependent conductivities σ(N,T) are shown to collapse onto a single universal curve using finite temperature scaling of a form σ(N,T) ∝ Tx f(|N/Nc - 1|/Ty) with x 0.38 and y 0.32 for the very small region of N = Nc ± 0.004Nc. The conductivity critical exponent μ = x/y = 1.2 ± 0.2 found from this analysis is significantly larger than μ 0.5 found from the analysis we performed previously on the same series of samples covering the much larger region of the concentration Nc c. Determination of the true critical region, either N = Nc ± 0.4% or N = Nc ± 40%, is necessary in the future for the reliable determination of μ in Ge:Ga.

引用

页码：631 / 637