Predictions and Magnetic Characterization of M-type Hexaferrites Doped with Two Cations in the Fe3+ Site

A theoretical and experimental study of magnetic properties of M-type barium hexaferrites, doped with two cations in the Fe3+ sites: (Co3+, Al3+), (Co2+, Ti4+) and (Co2+, Sn4+) is reported. The theoretical predictions were made using the generalization of a model on the distribution of dopants in the crystallographic sites under study. This approach allows a better interpretation of the kinetics of obtaining the samples from the structural and magnetic characterization. In the reported model, the maximum limit refers to theoretical optimum parameters. With these concepts, were established quantitative relationships between dopant amount per crystallographic site and magnetic properties predicted of these systems. The comparison between the experimental values and the predicted magnitudes showed that, in general, the samples were obtained with parameters obtained close to the theoretical ones for traditional ceramic methods. Such an approach is rarely taken into account in the reported bibliography.