Gadolinium-substituted W-type hexaferrites BaCo2Fe16-xGdxO27 (0.00 \(\le\) x \(\le\) 0.20) nanomaterials were fabricated using the sol–gel method. Structural, spectral, and dielectric characteristics of all the prepared hexagonal ferrites were evaluated. XRD analysis demonstrated that these nanoparticles had a pure phase W-type structure. With increasing the gadolinium substitutions, the crystallite size values show a decreasing trend ranging from 33.63 to 36.58 nm. Lattice constant and volume (Vcell) vary because the substituted and Fe3+ ions have different ionic radii. The behavior of local symmetry in manufactured crystals and the ordering procedure in nano-crystalline ferrites were studied using FTIR spectroscopy. W-type hexagonal ferrite structure was validated by FTIR analysis, which detected waves with a range of 400–3500 cm−1. Raman spectra were used to study the vibrational and rotational energy states. The Raman spectra revealed the distinctions between the substituted and unsubstituted samples. XPS spectra were employed to confirm the elemental composition. The XPS survey displayed that the hexagonal structure had fully developed because its results resembled the XRD patterns and FTIR spectra in every way. The dielectric measurements have been determined as a function of frequency (1–6 GHz), and the Maxwell–Wagner and Koop theories described each sample’s performance. Gd-doped BaCo W-type hexagonal ferrites with x = 0.20 and x = 0.15 depicted RL values of − 42 dB, − 39 dB at 1.25 GHz and 1.12 GHz, respectively. The results demonstrated that samples could be utilized for MLCIs and microwave absorption applications in the GHz region.
