Magnetic Granulometry and Super‐Paramagnetism
作者:
C. P. Bean,
I. S. Jacobs,
期刊:
Journal of Applied Physics
(AIP Available online 1956)
卷期:
Volume 27,
issue 12
页码: 1448-1452
ISSN:0021-8979
年代: 1956
DOI:10.1063/1.1722287
出版商: AIP
数据来源: AIP
摘要:
The magnetic technique of particle size measurement based on the work of Elmore consists of a comparison of a modified Langevin curve with the observed magnetization curve for an appropriate system of ferromagnetic particles. The average magnetic moment per particle is obtained from this analysis, and the average particle size is thus determined. The prediction by Ne´el of thermal relaxation in single‐domain ferromagnetic particles broadens the range of applicability of the granulometry method, with special emphasis on the size range from 20 A to about 100 A. A possible objection to the method, arising from evidence for an abnormal temperature dependence of the saturation magnetization of very small magnetic particles, is re‐examined experimentally and found to be invalid. Several examples are presented that demonstrate the predicted thermal relaxation and that point to a wide utilization of the granulometry technique.
点击下载:
PDF
(364KB)
返 回