The demagnetizing field on the surface of disc-shaped ferromagnetic samples

The local demagnetizing fields on the surface of flat cylindrical samples (disc) are measured by means of the free radical electron paramagnetic resonance for several thickness-to-diameter ratios from 0·01 to 0·15 and at two values of the external magnetic field (around 4 and 14 kOe). An empirical expression for the demagnetizing field intensity is found and anisotropy of the demagnetizing field is detected in the sample plane. The experimental results are compared with the conclusions of the theory of Joseph and Schlömann.We would like to thank to Mrs J.Smolíková for her help with the evaluation of the results and to Drs. R.Gemperle and V.Kamberský for many valuable suggestions to this problem.