EBSD Analysis of Crystal Orientation Distribution and Angular Dependence of Remanence in Sr-Ferrite and Nd-Fe-B Magnets

Electron backscatter diffraction (EBSD) provides an area-weighted crystal orientation distribution (AW-COD), whereas magnetic properties such as remanence are governed by the volume-weighted crystal orientation distribution (VW-COD). To bridge this gap, we developed a method to estimate VW-COD from EBSD-derived AW-COD and applied it to Sr-ferrite and Nd-Fe-B sintered magnets. In Sr-ferrite, crystal orientation exhibits strong grain-size dependence, leading to a significant difference between VW-COD and AW-COD. In contrast, the grain-size dependence in Nd-Fe-B is minimal, and the two distributions nearly coincide. The angular dependence of remanence was calculated using both distributions and compared with experiments. For Nd-Fe-B, calculations based on AW-COD and VW-COD both agree well with measurements, whereas for Sr-ferrite, VW-COD yields good agreement. These results demonstrate that VW-COD is essential for quantitative discussion of magnetic properties in materials with grain-size-dependent orientation.