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 Pr 3+ –Co 2+ substitution on the structural, optical, and electromagnetic interferrence (EMI) shielding properties of M-type strontium hexagonal ferrites with chemical composition Sr 1− x Pr x Fe 12− y Co y O 19 ( 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 °C for 4 h and sintered at 950 °C for 5 h. XRD analysis shows that the sample exhibits pure crystalline phase with no presence of impurity such as α-Fe 2 O 3 . The presence of three prominent peaks at 434, 543, and 586 cm −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 Pr 3+ –Co 2+ concentration. The maximum EMI shielding effectiveness of 27.40 dB at 18 GHz was obtained for the sample S2 which is above the commercial level of 20 dB.