Curling reversal mode in nonellipsoidal ferromagnetic particles

In the appropriate size range it can be argued that the absolute value of a negative curling nucleation field in a prolate spheroid is a good approximation for the switching field in any regularly shaped ferromagnetic body, which has the same volume, provided the correct demagnetizing field is used. An example is given for the case of a square prism. The discrepancy between this theory and some experimental results is claimed to be due to volume and surface anisotropies in the experimental particles. (C) 1999 American Institute of Physics. [S0021-8979(99)08414-5].