Abstract

A consistent theory of linear and nonlinear (cubic) initial susceptibilities of an assembly of uniaxially anisotropic noninteracting fine magnetic particles is presented. The expressions for the static (equilibrium) susceptibilities are obtained directly from the pertinent statistical thermodynamics. The contributions of anisotropy emerge yet in the first order and are analyzed for random and axes-aligned distributions. The ac susceptibilities are studied on the basis of the micromagnetic Fokker-Planck equation. Both a numerically exact solution for arbitrary frequency and a reliable low-frequency approximation are given. The obtained description proves to be more accurate as compared to the one based on the customary superparamagnetic blocking model. The results are used for a quantitative interpretation of recently published set of data on Co-Cu precipitating alloys. In this connection the choice of the particle size-distribution function is discussed.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.