Accession Number : AD0615589

Title :   OBSERVATION OF SUPERPARAMAGNETISM BY THE MOSSBAUER EFFECT,

Corporate Author : WEIZMANN INST OF SCIENCE REHOVOTH (ISRAEL)

Personal Author(s) : Shtrikman,S. ; Treves,D. ; Schuele,W. J.

Report Date : 15 NOV 1964

Pagination or Media Count : 9

Abstract : Mossbauer spectra of Fe57 in ultrafine NiFe2O4 and CoFe2O4 powders were studied, as a function of crystallite size and temperature. The hyperfine field was found to collapse at a temperature, lower than the Curie points which decreases with particle size. This collapse of the hyperfine field is interpreted as motional narrowing due to the onset of superparamagnetism. (Author)

Descriptors :   (*PARAMAGNETIC MATERIALS, MOSSBAUER EFFECT), (*HYPERFINE STRUCTURE, MOSSBAUER EFFECT), (*POWDERS, FERROMAGNETIC MATERIALS), HYSTERESIS, PARTICLES

Distribution Statement : APPROVED FOR PUBLIC RELEASE