La-doped Sr-hexaferrite particles were prepared by using sol-gel method. Post-preparation calcination with the aim of improving the magnetic properties of the as-synthesized particles was conducted at temperatures ranging from 800°C to 1050°C for 2 h in air. The effects of the calcination temperature and the La concentration (x = 0 - 0.15) on the crystallography, the particle morphology and the magnetic properties of La-doped Sr-hexaferrite were investigated by using X-ray diffraction (XRD), transmissions electron microscopy (TEM) and vibrating sample magnetometry (VSM). At a calcinations temperature of 850°C, the intrinsic coercivity (iHC) reached a maximum value of 7 kOe for the sample with x = 0.05 and the saturation magnetization (Ms) reached 72 emu/g after calcination at 1050°C.
