Le phénomène de superparamagnétisme
Year: 1981
Type: article
Abstract: Superparamagnetism phenomenon are reviewed. A short historical account of the first significant measurements and a short review of the topics where the study of the superparamagnetism bring pertinent results are done in the introduction. The theory of the phenomenon is studied in the first part. The Néel's model and the Brown's model are discussed in detail. The asymptotic values of the relaxation time are compared with the numerical solutions of Aharoni. Several chapters discuss the anisotropy energies and their effects on the barrier energy, the rotation mode of the spin particles and the antiferromagnetic particles. The different measurements are studied in the second part. At once, problems of general interest are analysed, i.e. : the measuring time, the blocking temperature, the effects of a diameter distribution... Afterwards the different measurements are reviewed from both theoretical and experimental points of view : magnetization, remanent magnetization, hysteresis loop, susceptibility, a.c. susceptibility, magnetoresistance, Mössbauer effect and FRM. Some examples are given.
Source: Revue de Physique Appliquée
Author: J.L. Dormann
Institution: Centre National de la Recherche Scientifique
Language: French
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1972924265