Determination of the effective magnetic anisotropy constant of ferrite nanoparticles dispersed in organic matrix

作者：Mihaela Osaci^*

来源：Indian Journal of Physics and Proceedings of the Indian Association for the Cultivation of Science, 2008, 82(12): 1671-1679.

• Fine-particle systems
• magnetic properties
• nanoparticles
• composite materials

With increasing interest in realising new magnetic materials, the magnetic behaviour of the nanoparticle disperse systems became an important problem both from the experimental point of view and from the theoretical one. The researches performed in the last period show that, by controlling the size distribution, the effective anisotropy constant and the nanoparticle concentration, the nanoparticle disperse systems can be used for realising magnetic materials with special properties. This paper presents a modality to determine the effective anisotropy constant of the mixed ferrite nanoparticle of NiZn, dispersed in the solid organic dielectric matrix - Nestrapol 450. In this respect, there are realised samples with low nanoparticle concentration, which are studied in dynamic magnetic fields through the Q-metric method, using a coaxial transmission line in short-circuit. So, it can determine the dependence of the complex magnetic permeability components, the tangent of the magnetic loss angles and material quality factor, on the frequency, and then we can calculate the medium Neel relaxation time and the effective anisotropy constant of the nanoparticles.

• 出版日期2008-12