Tuning the ferromagnetic resonance by doping strontium hexa-ferrite nanopowders

Mg-Ti substituted strontium hexa-ferrites nanopowders (SrFe12-x (MgTi) O-x/2(19), x = 0-3) were prepared by the sol-gel method. The morphology, structure and composition of the nanostructures were examined by field emission scanning electron microscopy (FESEM) and X-ray diffraction. The effect of Mg-Ti doping on the magnetic properties of the powders was investigated by vibrating sample magnetometry (VSM) and ferromagnetic resonance (FMR) at ambient temperature. Experimental results showed that the materials exhibit hexagonal structures with tunable magnetic properties. The saturation magnetization and the coercive field (H (c)) decreased through the Mg and Ti substitution. FMR proved that by incorporation of Mg and Ti in strontium ferrite lattice, crystalline anisotropy, and microwave absorption can be tuned. SrFe12-x (MgTi) O-x/2(19) ferrites are good candidate for applications at X-band microwave frequencies. A low field absorption signal was observed with the same phase as the FMR absorption in all doped ferrites. [GRAPHICS] .