Evaluation of mobility range of charge carriers at microwave region in Cr substituted [formula omitted]-CdFe2O4 ferrites

Abstract

A series of chromium-substituted cadmium post-spinel ferrites CdCrxFe2-xO4 (x = 0.0, 0.1, 0.3, 0.5) have been synthesized through the sol-gel auto-ignition method. The structural, vibrational, dielectric, magnetic, and microwave absorption properties of β-spinel ferrites through modern techniques which include X-ray diffraction, FTIR Spectroscopy, and Vector network analyzer. X-ray diffraction technique was used for structural investigation which confirmed the monophasic orthorhombic structure of prepared samples and a detailed study revealed that no impurity/additional phases were detected. Crystallite size and strain were extracted via the Williamson-Hall (W–H) method and Size strain plot (SSP). Vibrational spectroscopy (FTIR) successfully verified the spectral qualities of studied ferrites as measured wave number ranges between 400 and 600 cm−1. X-ray photoelectron spectroscopy verified that all metal ions exist and possess the corresponding electronic states. Electrical properties have been investigated at the microwave region (1 MHz – 6 GHz). The conduction mechanism has been studied via Johnscher power law. The Cole-Cole plot of all the samples consisting of two semicircles corresponding to grain and grain boundaries described the increasing conduction phenomena. In the present research, stable dielectric constant, dielectric loss, enhanced magnetic characteristics, and minimum reflection loss (−31.9 dB) make these CdCrxFe2-xO4 nano-crystallites most suitable candidates for highly dense and high-frequency microwave devices for EMI shielding material.