Hopping Conduction and Metal-Insulator Transition in Isotopically Enriched Neutron-Transmutation-Doped {sup 70}Ge:Ga

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.77.4058· OSTI ID:389398

Itoh, K M; Haller, E E; Beeman, J W; Hansen, W L; Emes, J; Reichertz, L A; Kreysa, E; Shutt, T; Cummings, A; Stockwell, W; Sadoulet, B; Muto, J; Farmer, J W; Ozhogin, V I ^[1]

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1. Department of Applied Physics and Physico-Informatics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223 (Japan)

We report on the electrical conductivity {sigma} of a series of nominally uncompensated neutron-transmutation-doped isotopically enriched {sup 70}Ge:Ga samples with the Ga concentration [Ga] near {ital N}{sub {ital c}} for the metal-insulator transition. {sigma} of all insulating samples obeys ln{sigma}{proportional_to}{minus}({ital T}{sub 0}/{ital T}){sup 1/2} with {ital T}{sub 0}{proportional_to}({ital N}{sub {ital c}}{minus}[Ga])/{ital N}{sub {ital c}} while the zero temperature conductivity {sigma}(0) of the metallic samples is {sigma}(0){proportional_to}{l_brace}([Ga]{minus}{ital N}{sub {ital c}})/{ital N}{sub {ital c}}{r_brace}{sup {nu}} with the critical exponent {nu}{approx_equal}0.5. The values of {ital N}{sub {ital c}} obtained from the two independent scalings of {ital T}{sub 0} and {sigma}(0) are identical, i.e., {nu}{approx_equal}0.5 is established unambiguously for uncompensated Ge:Ga. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 389398
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 19 Vol. 77; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
GALLIUM ADDITIONS
GERMANIUM 70
HOPPING
ISOTOPE ENRICHED MATERIALS
LAWRENCE BERKELEY LABORATORY
METAL-INSULATOR TRANSFORMATIONS
TEMPERATURE DEPENDENCE
TRANSMUTATION