THE FREQUENCY-DEPENDENT ELECTRICAL CONDUCTIVITY OF POWDERS: NICKEL OXIDE,
Abstract
The frequency-dependent conductivity of powered NiO, both undoped and doped with Cr (3+) was studied. A qualitative discussion is given of the causes of conductivity dispersion in owdered materials. Both the effects of the powder structure--interparticle contacts, surface resistance, etc--and of intrinsic losses independent of the powder structure--dielectric losses, hopping-type conductivity, etc--are considered. In undoped NiO it is argued that the observed conductivity dispersion is due to the hopping type of conductivity which masks any possible structure due to the powdered nature of the material. In Cr (3+) -doped NiO, however, a structure observed in the frequency-dependent conductivity is interpreted as being caused by a nonuniform distribution of Cr (3+), the Cr (3+) being concentrated on the surface of the powder particle. Additional evidence confirming this interpretation is given. An unexplained high-frequency, temperatureindependent loss in Cr (3+)-doped NiO has been observed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 17, 1963
- Accession Number
- AD0424878
Entities
People
- D. P. Snowden
- H. Saltsburg
- J. H. Pereue Jr.
Organizations
- General Dynamics