In this investigation, strontium hexaferrite nanocomposites co-doped with aluminum and chromium were prepared Sr(AlCr)xFe(12-2x)O19 with x different amounts (x= 0, 0.2, 0.4, 0.6 and 0.8), were synthesized. The magnetic nanocomposites have been prepared by simple sol-gel auto-combustion method. The morphology and structure of nano-samples were determined by FTIR, XRD and FESEM . The results of the XRD pattern confirmed P63/mmc space group and the single phase of the synthesized samples. The crystal size of the prepared samples decreases with increasing Al and Cr.The magnetic properties of these compounds are determined by the VSM. Magnetic properties (Mr, Ms and Hc) were measured. The result showed that Mr and Ms decrease with the increase of Al and Cr. پرونده مقاله