Structure, magnetic and magneto-optical properties of La-Ca-Co substituted strontium ferrites

Strontium ferrites Sr0.70-xLa0.3CaxFe11.7Co0.3O19 (x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30)，according to the formula Sr1-x-yCaxLay∙Fe12-yCoyO19, were prepared by the conventional ceramic process. The structure, morphology, optical, magnetic properties and transverse magneto-optical Kerr effect of the samples were studied by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscope (SEM) and magneto-optical ellipsometry. It is found that the samples are single phase except the samples with the largest substitution amount, x = 0.25 and x = 0.30. Doping with Ca2+, the coercivity of these material magnets is increased while their magnetization is nearly unchanged. In all cases, a strong transverse magneto-optical Kerr activity appears according to the optical and magneto-optical spectra of the samples.This work was financially supported by the National Natural Science Foundation of China under [grant numbers. 51272003 and 51472004], the Program of the Education Department of Anhui Province [grant numbers. KJ2012A027 and KJ2013B057], and from the Research Fund for the Doctoral Program of Higher Education of China under [project number 20123401110008], and from the Spanish Ministry of Education and Science under [project number MAT2009-14534-C03-03].Peer Reviewe