Accession Number : AD0287954

Title :   RESEARCH ON SPONTANEOUS MAGNETIZATION IN SOLID BODIES

Corporate Author : FRANKLIN INST PHILADELPHIA PA

Personal Author(s) : NEAVES,A.

Report Date : APR 1962

Pagination or Media Count : 1

Abstract : A series of very fine particle ferrites ranging in size from 18 to 200 Angstroms was s bjected to magnetic resonance investigation. These particles show an increasing shift in resonance field with decreasing particle size. The behavior of this shift with decreasing temperature is more complicated. These and other results are discussed on the basis of 2 ferromagnetic resonance equations. The first of these equations removes the restrictions generally imposed in the derivation of the equation of ferromagnetic resonance. This equation should be useful in the description of resonance in macroscopic single crystal ferrites. The second equation takes account of the superparamagnetic nature of the particles and predicts results qualitatively in agreement with those observed. Some work on nickel oxide particles exhibiting weak ferromagnetic and superparamagnetic effects is described. (Author)

Descriptors :   *FERRITES, *FERROMAGNETIC MATERIALS, *FERROMAGNETISM, COBALT ALLOYS, GOLD ALLOYS, MATHEMATICAL ANALYSIS, NICKEL COMPOUNDS, NUCLEAR MAGNETIC RESONANCE, OXIDES, PARAMAGNETIC RESONANCE, PARTICLES, SINGLE CRYSTALS

Distribution Statement : APPROVED FOR PUBLIC RELEASE