Electrical properties and conduction mechanisms of Ru-based thick-film (cermet) resistors

Journal Article · Thu Dec 01 04:00:00 EST 1977 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.323595· OSTI ID:5362826

Pike, G E; Seager, C H

This paper presents an experimental study of the electrical conduction mechanisms in thick-film (cermet) resistor. The resistors were made from one custom and three commercially formulated inks with sheet resistivities ranging from 10/sup 2/ to 10/sup 6/ ..cap omega../D/sup 7/Alembertian in decade increments. Their microstructure and composition have been examined using optical and scanning electron microscopy, electron microprobe analysis, x-ray diffraction, and various chemical analyses. This portion of our study shows that the resistors are heterogeneous mixtures of metallic metal oxide particles (approx.4 x 10/sup -5/ cm in diameter) and a lead silicate glass. The metal oxide particles are ruthenium containing pyrochlores, and are joined to form a continuous three-dimensional network of chain segments. The principal experimental work reported here is an extensive study of the electrical transport properties of the resistors. The temperature dependence of conductance has been measured from 1.2 to 400 K, and two features common to all resistors are found. There is a pronounced decrease in conductance at low temperatures and a shallow maximum at several hundred Kelvin. Within the same range of temperatures the reversible conductance as a function of electric field from 0 to 28 kV/cm has been studied. The resistors are non-Ohmic at all temperatures, but particularly at cryogenic temperatures for low fields. At higher fields the conductance shows a linear variation with electric field. The thick-film resistors are found to have a small dielectric constant and a (nearly) frequency-independent conductance from dc to 50 MHz. The magnetoresistance to 100 kG, the Hall mobility, and the Seebeck coefficient of most of the resistors have been measured and discovered to be quite small. Many of the electrical transport properties have also been determined for the metal oxide particles which were extracted from the fired resistors.

• Research Organization: Sandia Laboratories, Albuquerque, New Mexico 87115
• OSTI ID: 5362826
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 48:12; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
42 ENGINEERING
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
BISMUTH COMPOUNDS
BISMUTH OXIDES
CERMETS
CHALCOGENIDES
CHEMICAL COMPOSITION
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
EQUIPMENT
FILMS
HALL EFFECT
INKS
MAGNETORESISTANCE
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RESISTORS
RUTHENIUM COMPOUNDS
RUTHENIUM OXIDES
SEEBECK EFFECT
STRESSES
TEMPERATURE DEPENDENCE
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TUNNEL EFFECT