Radial magnetometric demagnetizing factor of thin disks

The radial magnetometric demagnetizing factor N/sub mr/ of a disk is calculated from the corresponding axial factor N/sub ma/ as a function of the ratio of thickness to diameter t/d and the susceptibility of material /spl chi/ by the formula N/sub ma/(t/d, /spl chi/= /spl chi/*) +2N/sub mr/[t/d, /spl chi/=-/spl chi/*/(l +/spl chi/*)] =1+/spl delta/(t/d, /spl chi/*). This formula is derived from the magnetostatic laws with a correction (|/spl delta/|/spl Lt/1) based on known values of N/sub ma/ and N/sub mr/ for /spl chi/*=/spl infin/. The accuracy of the N/sub mr/ thus obtained is estimated to be better than 1%, which satisfies most practical needs.