Resistivity and resistivity fluctuations of thin-film platinum-aluminum oxide granular metal-insulator composites

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

OSTI ID:5284174

Mantese, J V

Thin film metal-insulator composites were used to study how the resistivity and fluctuations in the resistivity were altered by changes in conduction mechanism so as to understand the source of the fluctuations and to better understand the conduction processes themselves. Metal-insulator composites were prepared by co-evaporation of platinum and aluminum oxide in a high vacuum system to create a series of films which had a range of metal volume fill fractions, p, from 23 to 100%. The samples were patterned using standard photolithographic techniques to form sample geometries of typical dimensions, length approx.40 ..mu..m, width approx.2 ..mu..m, and thickness approx.1500 A. The resistivity rho, and power spectral density of the resistivity fluctuations, S/sub rho/(f), were measured as a function of p and temperature, T. Rho(p,T) was found to be a rapidly increasing function of decreasing p, rising monotonically by more than 7 orders of magnitude as p was decreased from 100% to 23%. For p greater than or equal to 59% the resistivity decreased linearly with decreasing temperature until limited by impurity scattering. The resistivities for the low metal fill fraction materials (P greater than or equal to 50%) increased as the temperature was reduced as expected of thermally assisted tunneling conduction in metal-insulator composites. The transition from metallic conduction to thermally assisted tunneling occurred at a critical value, p/sub c/, between 59% and 50% Pt.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 5284174
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
ELECTRIC CONDUCTIVITY
FABRICATION
ALUMINIUM OXIDES
PLATINUM
THIN FILMS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
MATERIALS
METALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLATINUM METALS
TRANSITION ELEMENTS
360304* - Composite Materials- Physical Properties- (-1987)