Microwave absorption studies of nanocrystalline SrMnx/2(TiSn)x/4Fe12−xO19 prepared by the citrate sol–gel method

Electromagnetic wave absorption properties were investigated in the Mn–Ti–Sn substituted strontium M-type hexagonal ferrites (SrMnx/2(TiSn)x/4Fe12−xO19) prepared by the citrate sol–gel method. The crystalline structure, size, coercivity and microwave absorption properties of the particles were investigated by means of X-ray diffraction, transmission electron microscopy (TEM), vibrating sample magnetometry and a vector network analyzer. Results showed that the materials have hexagonal structures with high purity. Based on microwave measurements on reflectivity, SrMnx/2(TiSn)x/4Fe12−xO19 may be a good candidate for electromagnetic compatibility and other practical applications at high frequency. A wide bandwidth of microwave absorption is obtained in the composite samples containing ferrite powders with composition x=2x=2 and x=3x=3 in X-band frequencies. A minimum reflection loss of −39 dB was observed at 9.7 GHz for a sample of x=3x=3. It should be noted that thicknesses of the absorbers are only 1.6 mm.

► Sn–Ti–Mn substituted Sr ferrites were prepared by the citrate sol–gel method. ► The XRD characterization confirmed the formation of a simple hexagonal phase. ► Microwave absorption properties have been discussed in X band. ► The band width of 2.7 GHz was obtained with RL>−20 dB for SrMn(SnTi)0.5Fe10O19. ► The thicknesses of the absorbers are only 1.6 mm.