Insight of structural, dielectric and spectroscopic characteristics of Ba0.6Sr0.4-xYbxFe12-yCoyO19 M-type hexaferrite

Ba0.6Sr0.4-xYbxFe12-yCoyO19, (0.0 <= x <= 0.125, 0.0 <= y <= 1.25) M-type hexaferrite were synthesized using the auto combustion sol-gel process. The synthesized samples were then sintered at 1200 degrees C for 5 h in a muffle furnace. XRD, FTIR, Raman, and Photoluminescence spectroscopies were used to analyse all the samples. XRD technique was used for structural examination of Ba0.6Sr0.4-xYbxFe12-yCoyO19. The XRD patterns of Yb-Co co-substituted Mtype hexaferrites revealed the pure single phase of synthesized samples. Change in Yb-Co concentration influenced lattice parameters and unit cell volume. The variations in lattice constants "a" and "c" values are 5.891-5.862 and 23.180-23.317. FTIR spectroscopic data graphs revealed the formation of several absorption bands from 430 cm-1 to 3000 cm-1. The strain in the unit cell produced by substitution changes in Raman spectra which is also confirmed by XRD. Many 630 nm-700 nm emissions were observed in the PL spectra of Ba0.6Sr0.4-xYbxFe12-yCoyO19. Furthermore, a bandgap of 1.961-1.875 eV was observed for the pure sample. The substitution improves the dielectric losses and Ac conductivity. The Maxwell-Wagner theory was used to investigate the changing trends of characteristics regarding dielectric parameters. The findings show that the samples with the appropriate cationic substitution can be used in microwave and high-frequency applications.