Study on the Magnetic Properties and Domain Structure of NdFeNbZrB Nanocomposite Permanent Magnets
A new kind of nanocomposite rare-earth magnets of Nd2Fe14B/ α-Fe were prepared by melt-spinning method. Effects of alloying element and processing parameter on the microstructure and magnetic properties of nanocomposite materials have been investigated. Zr is effective to enhance coercivity of alloys because of a refinement of grains, so that in alloy of Zr content with 1.0 at% (Zr1.0) has the smallest grain size of 17 nm and therefore causes the highest intrinsic coercivity . Addition of Zr can also enhance the ability of amorphous-forming. The combination of adding of Zr and using a smaller diameter of the nozzle in the melt-spinning method is effective for the forming of amorphous structure. According to the MFM study, the length of the magnetic contrast in the alloy is much larger than the mean grain size. The large length corresponds to that of interaction domains(ID), which is related to the exchange coupling effect.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
W.Y. Qin et al., "Study on the Magnetic Properties and Domain Structure of NdFeNbZrB Nanocomposite Permanent Magnets", Materials Science Forum, Vols. 539-543, pp. 3303-3308, 2007