Electrical Properties of Isotopically Enriched Neutron-Transmutation Doped ^{70} Ge:Ga near the Metal-Insulator Transition

Authors:
  • MWMichio Watanabe
    Michio Watanabe
  • YOYouiti Ootuka
    Youiti Ootuka
  • KIKohei M. Itoh
    Kohei M. Itoh
  • EHEugene E. Haller
    Eugene E. Haller
Preprint
Publisher website
Google Scholar
Abstract
We report the low temperature carrier transport properties of a series of nominally uncompensated neutron-transmutation doped (NTD) ^{70} Ge:Ga samples very close to the critical concentration N_c for the metal-insulator transition. The concentration of the sample closest to N_c is 1.0004N_c and it is unambiguously shown that the critical conductivity exponent is 0.5. Properties of insulating samples are discussed in the context of Efros and Shklovskii's variable range hopping conduction.