Electron spin resonance measurements of a demagnetizing field on the surface of metal samples

By comparing the signals of electron spin resonance (ESR) from two crystals of a diamond (spin-labels) the demagnetizing field of the Co, Fe, and Ni samples in the shape of strongly elongated ellipsoids of revolution (disks) has been measured. The magnetic permeabilities of the metals in the external magnetic field corresponding to the ESR of the broken chemical bonds in a natural diamond irradiated with fast reactor neutrons have been determined.