Al2O3 additions to Fe‐Nd‐B magnets: Can pinning be achieved? (abstract)

One of the aspects currently under investigation in Fe‐Nd‐B magnets is that of the temperature dependence of iHc and Br, which are quite high. In this paper a method to overcome this is suggested. It is well known that pinning of domain walls by a second phase, whose magnetic properties are vastly different from those of the matrix, can be very effective when the particle size is about equal to the wall width. With this knowledge, 300‐Å nominal size Al2O3 particles have been added to Fe‐Nd‐B in order to improve its iHc as well as the temperature dependence. For a 1 wt. % addition, a 10% increase in the iHc was noted. Results of magnetic property measurements, microstructural observations as well as Lorentz microscopy will be presented in this paper. © 1988, American Institute of Physics. All rights reserved.