ON THE USE OF COMPLEX SUSCEPTIBILITY DATA TO COMPLEMENT MAGNETIC VISCOSITY MEASUREMENTS

Magnetic viscosity measurements consist of placing an ensemble of small magnetic particles in a very large magnetic field, which tends to align the magnetic moments, m(p), of the particles in the direction of the field and then observing the decay, with time, of the magnetization when the field is removed. In measuring the magnetic viscosity, it is possible for magnetization data to be unavoidably lost due to the time delay between removing the applied field and making the first magnetization measurement. It is shown that, by taking the inverse Fourier transform of the frequency-dependent complex susceptibility, chi(omega) = chi'(omega) - i(chi)''(omega), of the sample, it is possible to recover data corresponding to that which would have been measured during the period of the time delay.