We have measured the electrical conductivity of Ge:Ga samples prepared by neutron-transmutation doping of isotopically enriched 70Ge single crystals in order to study the metal-insulator transition (MIT) ruling out an ambiguity due to inhomogeneous distribution of impurities. The critical exponent for the zero-temperature conductivity is 0.5 in zero magnetic field and 1.1 in magnetic fields. Variable-range-hopping conduction of the insulating samples and finite-temperature scaling analysis of the MIT induced by the external magnetic field are also discussed.
@article{arxiv.cond-mat/0008138,
title = {Metal-Insulator Transition in Homogeneously Doped Germanium},
author = {Michio Watanabe},
journal= {arXiv preprint arXiv:cond-mat/0008138},
year = {2007}
}
Comments
LaTeX2e, 21 pages with 15 embedded figures, to be published in M. F. Thorpe and J. C. Phillips (eds.), "Phase Transitions and Self-Organization in Electronic and Molecular Materials" (Kluwer Academic/Plenum Publishers)