Metal-insulator transition and superconductivity in amorphous molybdenum-germanium alloys

Title: Metal-insulator transition and superconductivity in amorphous molybdenum-germanium alloys

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Abstract

The electrical and thermodynamic properties of amorphous molybdenum-germanium alloys in three dimensions were studied as a function of composition was well as temperature. Homogeneous amorphous molybdenum-germanium films were synthesized over a wide compositional range by co-sputtering from pure molybdenum (Mo) and pure germanium (Ge) targets. Physical properties of the films were investigated by electrical conductivity, tunneling, magnetoresistance, low-temperature specific heat measurements, and superconductivity. Experimental results were analyzed by the recent theories of localization and electron interaction. Behavior of the superconducting transition temperature T/sub c/ as a function of concentration can be correlated with the structural results of Kortright. Upper critical fields H/sub c2/ in the Mo-rich region show the enhancement of H/sub c2/ above the Wethamer-Helfand-Hohenberg-Maki (WHHM) theory, which is predicted by the renormalization of the Coulomb interaction due to effects of weak localization. However, H/sub c2/ near the M-I transition shows a behavior below the WHHM fit, which has not been predicted by strong localization theories.

Authors:: Yoshizumi, S

Publication Date:: 1986-01-01

Research Org.:: Stanford Univ., CA (USA)

OSTI Identifier:: 7252876

Resource Type:: Thesis/Dissertation

Resource Relation:: Other Information: Thesis (Ph. D.)

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; GERMANIUM ALLOYS; PHASE STUDIES; SUPERCONDUCTIVITY; MOLYBDENUM ALLOYS; AMORPHOUS STATE; CHEMICAL COMPOSITION; TRANSITION TEMPERATURE; ALLOYS; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; PHYSICAL PROPERTIES; THERMODYNAMIC PROPERTIES; 360104* - Metals & Alloys- Physical Properties; 360102 - Metals & Alloys- Structure & Phase Studies

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                    Yoshizumi, S. Metal-insulator transition and superconductivity in amorphous molybdenum-germanium alloys.  United States: N. p., 1986. 
        Web.

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                    Yoshizumi, S. Metal-insulator transition and superconductivity in amorphous molybdenum-germanium alloys.  United States.

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                    Yoshizumi, S. Wed .  
        "Metal-insulator transition and superconductivity in amorphous molybdenum-germanium alloys".  United States.

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@article{osti_7252876,

  title        = {Metal-insulator transition and superconductivity in amorphous molybdenum-germanium alloys},

  author       = {Yoshizumi, S},

  abstractNote = {The electrical and thermodynamic properties of amorphous molybdenum-germanium alloys in three dimensions were studied as a function of composition was well as temperature. Homogeneous amorphous molybdenum-germanium films were synthesized over a wide compositional range by co-sputtering from pure molybdenum (Mo) and pure germanium (Ge) targets. Physical properties of the films were investigated by electrical conductivity, tunneling, magnetoresistance, low-temperature specific heat measurements, and superconductivity. Experimental results were analyzed by the recent theories of localization and electron interaction. Behavior of the superconducting transition temperature T/sub c/ as a function of concentration can be correlated with the structural results of Kortright. Upper critical fields H/sub c2/ in the Mo-rich region show the enhancement of H/sub c2/ above the Wethamer-Helfand-Hohenberg-Maki (WHHM) theory, which is predicted by the renormalization of the Coulomb interaction due to effects of weak localization. However, H/sub c2/ near the M-I transition shows a behavior below the WHHM fit, which has not been predicted by strong localization theories.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/7252876},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {1986},

  month        = {1}

}

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