Application of FORC distributions to the study of magnetic interactions in ferrites of composition Ba1-xLax+ƒÔFe12-xCoxO19

M. I. OLIVA; P. G. BERCOFF; H. R. BERTORELLO

Rio de Janeiro, Brasil

Workshop; VIII Latin American Workshop on Magnetism, Magnetic Materials and their Applications; 2007

Magnetic interactions in hexaferrite samples of Ba$_{1-x}$ La$_{x+\delta}$ Fe$_{12-x}$ Co$_x$ O$_{19}$  composition were studied. Theprecursor powders ---barium carbonate (BaCO$_3$), lanthanum oxide(La$_2$O$_3$), hematite (Fe$_2$O$_3$) and cobalt acetate--- weremilled for 100 hs in air atmosphere and heat--treated for one hourat 1000$^{\circ}$C. The structural characterization was performedby X ray diffraction. The FORCs distributions show a single peakat high switching fields, indicating the substituted systems areformed by weakly--interacting particles. Its observed that Laexcess induces the decoupling of the particles.