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

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:7252876

Yoshizumi, S

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.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 7252876
• Country of Publication: United States
• Language: English

Related Subjects

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