Erbium-chromium substituted strontium hexaferrite particles: Characterization of the physical and Ku-band microwave absorption properties

Abstract

A series of erbium-chromium substitution strontium hexaferrite particles with the nominal composition of SrErxCrxFe12-2xO19 was synthesized using the sol-gel auto-combustion method. The crystalline structure, magnetic and microwave absorption properties of the materials were investigated in detail. The TGA/DSC and XRD evaluations by the FULLPROF confirmed the successful substitution of Er and Al cations in the strontium hexaferrite lattice. Moreover, the VSM measurements confirmed that HC, and Mr continuousely decreased by increasing the erbium and chromium substitutions, while MS increases up to x = 0.2, followed by a reduction with the increased amount of the substitution. We also investigate the cause of the changes in the magnetic and microwave absorption properties through simultaneous substitution. The maximum reflection loss of −34.71 dB was observed in the SrEr0.5Cr0.5Fe11O19 sample with a bandwidth that covered the entire measured microwave frequency range of 12–18 GHz (Ku band). This finding suggested that x = 0.5 had effective absorbing characteristics, which is of great interests for the military radar in the Ku band.