Design of nano-sized Pr3+-Co2+-substituted M-type strontium hexaferrites for optical sensing and electromagnetic interference (EMI) shielding in Ku band

This research investigates the effect of Pr3+-Co2+ substitution on the structural, optical, and electromagnetic interferrence (EMI) shieldingproperties of M-type strontium hexagonal ferrites with chemical composition Sr1-xPrxFe12-yCoyO19 (x=0.0, 0.2, 0.4 and y=0.00, 0.15, 0.35). The sample was prepared by sol-gel auto-combustion technique, pre-sintered at 400 degrees C for 4h and sintered at 950 degrees C for 5h. XRD analysis shows that the sample exhibits pure crystalline phase with no presence of impurity such as -Fe2O3. The presence of three prominent peaks at 434, 543, and 586cm(-1) in FTIR spectra indicates the formation of hexaferrite phase. FESEM micrographs depict nanoparticles with hexagonal plate-like structure of hexaferrites which is vital for microwaves absorption, whereas EDX spectra show the host and substituted ions. The observed band gap was found to decrease with increase in Pr3+-Co2+ concentration. The maximum EMI shielding effectiveness of 27.40dB at 18GHz was obtained for the sample S2 which is above the commercial level of20 dB.