Analysis of magnetic disaccommodation in La@@u3+@-Co@@u2+@-substituted strontium ferrites

M-type strontium ferrites substituted by La@@u3+@-Co@@u2+@(Sr@@d1-@@@i@@dx@@La@@i@@dx@@Fe@@d12- @@@i@@dx@@Co@@i@@dx@@O@@d19@) were prepared by ceramic process. Effects of the substituted amount of La@@u3+@ and Co@@u2+@ on structure and magnetic properties of Sr@@d1-@@@i@@dx@@La@@i@@dx@@Fe@@d12- @@@i@@dx@@Co@@i@@dx@@O@@d19@ compounds have systematically been investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and magnetic disaccommodation. In the measurement range from 80 to 500 K, the magnetic disaccommodation is represented by means of isochronal curves. It is well known that magnetic disaccommodation cannot be obviously found in the M-type of pure strontium ferrites. However, three peaks were observed in Sr@@d1-@@@i@@dx@@La@@i@@dx@@Fe@@d12-@@@i@@dx@@Co@@i@@dx@@O@@d19@, and this behavior is explained in terms of the presence of Fe@@u2+@ cation and to the site occupation by the magnetic Co@@u2+@ ionic within the hexagonal structure.