A procedure to obtain the parameters of Curie temperature distribution from thermomagnetic and magnetocaloric data

We propose a procedure for the determination of the parameters of the Curie temperature distribution (TCD) in a compositionally inhomogeneous ferromagnetic material. Assuming a Gaussian TCD and using a mean field approach based on the Brillouin function, we report that with respect to the average value of the distribution: a) both inflection point of magnetization, T-inf, and temperature at maximum magnetic entropy change curves, T-pk(MCE), shift to lower temperatures and b) temperature at maximum paramagnetic susceptibility, T-pk(chi), shifts to higher temperatures. Using these evolutions as a function of the TCD broadening and fitting them to a second order polynomial function, a self-consistent procedure to determine the parameters of the distribution is supplied. These predictions have been experimentally tested for a ball milled Fe70Zr30 amorphous alloy using thermomagnetic and magnetocaloric measurements. The obtained parameters using the proposed procedure agree with those directly measured using Mossbauer spectrometry.