Structural and dielectric properties of Sr4Zn2Fe36O60 U-type hexaferrites with optimized Gd contents and sintered by a two-step process

The structural and dielectric properties of Gadolinium substituted U-type hexaferrites (Sr4Zn2Fe36O60) were investigated. The samples were synthesized via the Sol-gel auto combustion route. In a muffle furnace, these samples were sintered for 5 h at 1250 degrees C. The pellets of synthesized powder samples were characterized by XRD, PL, Dielectric, FTIR, and Raman spectroscopies. Structural elucidation of Sr4Zn2Fe36-xGdxO60 was done via XRD. The obtained XRD patterns were matched with the prior literature. The impact of Gd3+ substitutions was measured on all the lattice parameters. Lattice constants a and c were found between 5.871 and 5.900 angstrom and 111.76-112.23 angstrom, respectively. The PL spectra of Sr4Zn2Fe36-xGdxO60 demonstrated multiple emissions in the range of 630 nm-700 nm, and by analyzing PL spectroscopic results, a bandgap of 1.8742 eV was found for the un-doped sample. Many dielectric parameters, i.e., Dielectric constant (epsilon'), Dielectric losses (epsilon), Loss tangents (tan delta), Complex electric modulus (M' & M ''), and A.C conductivity (sigma ac) were investigated at room temperature by changing the frequencies from 1 GHz to 6 GHz. The varying trends of dielectric parameters were analyzed with the assistance of the Maxwell-Wagner model. Various absorption bands were observed in the range of 500-4000 cm-1 by plotting the FTIR spectroscopic results of Sr4Zn2Fe36-xGdxO60. Raman spectra demonstrated a combination of strong and fragile peaks in 1-1800 cm-1. The obtained results of various spectroscopies sug-gested that the prepared materials can be used extensively for different Micro-Wave attenuation purposes.

Automated summary

The structural and dielectric properties of Gadolinium substituted U-type hexaferrites were investigated. The samples were synthesized via a Sol-gel auto combustion route and characterized by various spectroscopic techniques. The results suggested that the prepared materials can be used extensively for different Micro-Wave attenuation purposes.