A Combined TEM/STEM and Micromagnetic Study of the Anisotropic Nature of Grain Boundaries and Coercivity in Nd-Fe-B Magnets

Figure 2

Electron density of the electron beam at the bottom surface of the TEM specimen, showing the electron beam broadening of a 1.5 nm (, red curve) wide beam with a semiconvergence angle of 6 mrad, which is focused on the surface of the 4 nm thick neodymium GB, which is surrounded by two Nd₂Fe₁₄B grains in the TEM specimen with varying thickness. Significant broadening of the incident electron beam occurs at a sample thickness > 50 nm.