In this paper, a batch of M- type strontium hexaferrite samples with nominal composition of SrFe12-xCoxO19(where x= 0- 2), have been synthesized via sol- gel method. In the synthesis of samples, first a precursor gel was prepared, and then dry- gel was calcined at 1000°C for 2 hours to obtain the nano- SrFe12-xCoxO19. The XRD results revealed that for SrFe12-xCoxO19 samples with x≤0.5, all of them have single- phase hexaferrite structure and also this data suggests that the F 3+ ions are substituted by Co2+ ions in the crystallography sites of the SrFe12-xCoxO19, but for the samples with x>0.5, the second phase of CoFe2O4 is appeared and suggests that the Co2+ ions also make a distinct phase in the samples. The magnetic properties, such as saturation magnetization (Ms), magnetic remanence (Mr), magnetic coercivity (Hc), squareness ratio (Mr/Ms), crystalline anisotropy field (Ha), energy product [(BH)max] and the susceptibility χ as the derivative of M with respect to H of the upper branch of the hysteresis loop were discussed by measurements of M-H curves with vibrating sample magnetometer (VSM). The magnetic measurements revealed that the coercively (Hc) values of all the samples decrease with increasing dopant contents.
Effect of microwave sintering on microstructural and magnetic properties of strontium hexaferrite using sol–gel technique