Effect of aluminum substitution on physical–chemical properties of novel iron-sillenite Bi25Fe(1−x)AlxO40 (x = 0.00, 0.20, 0.50)

Novel Sillenites Bi25Fe(1−x)AlxO40 (x = 0.00, 0.20, and x = 0.50) have been synthesized using the SSR method. In this paper, the effect of Al-substitution on the physicochemical properties was performed. The X-ray diffraction analysis as well as both Raman and FT-IR spectroscopies indicate that all the elaborated materials have a bcc structure with the I23 space group. The increase of the cell parameters, the morphological features, and thus the decrease of the grain size with Aluminum content is also evidenced via the X-ray patterns and SEM microscopy. DSC measurements highlighted the occurrence of various phenomena related to both structural and dielectric features. The temperature dependence of electrical conductivity and the deduced activation energies pointed to the effect of temperature on the conduction process. The impedance analysis on the samples confirms the onset of relaxation phenomenon in the sample with semiconducting behavior. Furthermore, an AFM-Paramagnetic transition for x = 0.00 and 0.20, with Neel temperatures of 268 and 265 K, respectively. Otherwise, paramagnetic behavior is observed for x = 0.50. The optical measurements make these materials suitable candidates for photocatalysis and optoelectronic applications.