Magnetic properties and microstructure of La-substituted BaCr-ferrite powders

A combustion process was used to synthesize crystalline powders of La-substituted barium chromium hexaferrites Ba_1 − xLa_xFe_11.5Cr_0.5O₁₉ (x = 0-0.25). The structures, morphologies and ferromagnetic properties of La³⁺ substituted nanocomposites were characterized by powder X-ray diffractometer (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). XRD results showed that single-phase barium chromium ferrite powders was found at La content x ≤ 0.2. From the SEM, it was observed that the particles calcined at 1100 °C had a plate-like hexagonal shape. The results of magnetic mensuration revealed that both M_S and H_C of barium hexaferrite increased up to x = 0.1, and then decreased with the increasing of La content.