Exchange-Coupling Effect of Nd₂Fe₁₄B/FeCo Nanocomposite by Colloidal Method

Abstract

Exchange-coupling effect of Nd₂Fe₁₄B/FeCo nanocomposite by colloidal method is reported. The magnetic hard phase Nd₁₅Fe₇₇B₈ alloy was prepared by high energy ball mill process and the magnetic soft phase Fe-Co nanoparticles was synthesized by coprecipitation method, and then were annealed in order to crystallize at the different temperature. The hard phase Nd₁₅Fe₇₇B₈ nanoparticles and the soft phase Fe-Co nanoparticles were coated with surfactants such as oleic acid. The hard and soft phase nanoparticles coated by surfactants were mixed by self-assembly with shake-milling process, and then annealed at 650°C for 20 min.

Keywords:

• coprecipitation
• exchange-coupling
• high energy ball mill process
• self-assembly

Acknowledgments

This work was supported by Korean National Research Laboratory Program. Chang Woo Kim would like to thank the financial support by the Brain Korea 21 project in 2006.