Lanthanum doped Zn0.5Co0.5LaxFe2-xO4 spinel ferrites synthesized via co-precipitation route to evaluate structural, vibrational, electrical, optical, dielectric, and thermoelectric properties

Lanthanum doped Zn0.5Co0.5LaxFe2-xO4 spinel ferrites were synthesized through the co-precipitation technique. To characterize the structural, vibrational, electro-optical, dielectric, and thermoelectric properties, the following characterization techniques X-ray diffraction (XRD), Fourier transformation infrared (FTIR) and Raman spectroscopy, I-V measurement analysis, UV-vis spectroscopy, LCR meter, Seebeck analysis, and Energy dispersive X-ray analysis (EDX) were used. The XRD patterns showed nano-crystalline single-phase structure formation. Moreover, the lattice constant increased from 8.3909 +/- 0.0042 angstrom to 8.3994 +/- 0.0042 angstrom, and the crystallite size reduced from 33.6 to 17.5 nm with increasing La3+ cations. The bond angles showed stronger A-A and A-B interactions and weak B-B interactions with the addition of La3+. FTIR spectra showed the existence of the M - O stretching band and functional group study. The resistivity, optical band gap, and activation energy had maximum values at x = 0.1. At room temperature (RT), the dielectric parameters were recorded between the range of 8 Hz to 8 MHz. The Seebeck voltage coefficient was obtained for the as-prepared nano-ferrites to determine the charge carrier type. The EDX spectra showed a compositional distribution of the elements in all the samples.