Document Details
PURL
(3 mb)
Title:
Effect of Neutron Irradiation on the Magnetic Properties of Graphitized Lampblack
Author(s):
Document Type:
REPORT
Publication Date:
1952 Dec 29
Declassification Date:
1997 Apr 08
Accession Number:
None
Document Number(s):
NAA-SR-MEMO-550
Originating Research Org.:
North American Aviation, Inc., Canoga Park, CA (United States)
OpenNet Entry Date:
2017 Oct 24
OpenNet Modified Date:
2026 Aug 21
Description/Abstract:
The magnetic properties of a graphitized lampblack, commercially designated as AS-25, differ markedly from those of other artificial graphites which have petroleum coke as their basic raw material. The negative Hall coefficient and large magneto-resistivity normally encountered are absent. Instead, one finds a slightly positive Hall coefficient and a markedly smaller magneto-resistivity. The magnetic susceptibility for both types of graphite, however, are quite similar. Now the susceptibility is known to be a good measure of the number of carriers. This would imply that the concentration of conduction electrons is approximately the same for both graphites. Hence, the scattering mechanism must be different for the two types. It is postulated that in the case of the graphitized lampblack, boundary scattering predominates due to the small crystallite size, whereas, in the case of the other AGOT and AWG graphites, intracrystalline scattering is the more important. An investigation of the effect of radiation upon the magnetic properties of graphitized lampblack should yield new information regarding the role of the two scattering parameters in the mechanism of radiation damage. It Is the purpose of this paper to present the results of such a study.