Synthesis and Characterization of Nd2Fe14B Powder Prepared by Using Milling and Heat Treatment

Abstract

The Nd2Fe14B powder has been made by using High Energy Milling (HEM) from mixed metal powders Iron (Fe), Neodymium (Nd) and Boron (B). The Nd, Fe and B powders were mixed according stoichiometric composition (atomic ratio Nd:Fe:B = 2 : 14 : 1) and milled with milling time 40 hours by using HEM. Toluene liquid was used as milling media to protect of metal powders from oxygen. The sample after milling was heated at temperature 600, 700 and 800 °C in vacuum condition (10-3 Pa) for one hour. The measurement result of x-ray diffraction show that the Nd2Fe14B phase already formed as dominant phase and Fe-phase after milling 40 hours, with magnetic remanence (mr) = 4.10 emu/g and coercivity = 1,5 kOe. After heat treatment at temperature 700°C , the sample has magnetic remanence (mr) = 78 emu/g and coercivity (Hc)= 2,0 kOe. But sample after heat tgreatment at 800°C became soft magnet with lower mr and Hc value.