Magnetic domain structures in thin foils of Nd2Fe14B have been computed from a one-dimensional model, which enables the domain width, domain wall width and domain magnetization direction to be calculated as functions of foil thickness and crystallographic orientation. The results have been compared with measurements made by Lorentz microscopy. Measurement of the domain wall width enables the exchange constant to be estimated.
Newnham, S. J., Jakubovics, J. P., & Daykin, A. C. (1996). Domain structure of thin NdFeB foils. Journal of Magnetism and Magnetic Materials, 157–158, 39–40. https://doi.org/10.1016/0304-8853(95)01132-3