Nonlinear dynamic susceptibilities of interacting and noninteracting magnetic nanoparticles

[摘要] The linear and cubic dynamic susceptibilities of solid dispersions of nanosized maghemite gamma -Fe2O3 particles have been measured for three samples with a volume concentration of magnetic particles ranging from 0.3% to 17%, in order to study the effect of dipole-dipole interactions. Significant differences between the dynamic response of the samples are observed. While the linear and cubic dynamic susceptibilities of the most dilute sample compare reasonably well with the corresponding expressions proposed by Raikher and Stepanov for noninteracting particles, the nonlinear dynamic response of the most concentrated sample exhibits at low temperatures similar features as observed in a Ag(11 at% Mn) spin glass. (C) 2000 Elsevier Science B.V. All rights reserved.

[发布日期] 2000-12-01

[关键词] maghemite;nanoparticles;nonlinear dynamic susceptibility