Rhombohedral distortion induced structural, magnetic, optical phase transitions and photocatalytic activity in Sm and Sm-Cr co-substituted bismuth ferrite nanoparticles

Abstract

Rhombohedral distortion induced structural, magnetic, optical phase transitions and photocatalytic activity of BiFeO3 (BFO), samarium (Sm)-substituted and Sm-Cr co-substituted bismuth iron oxide nanoparticles were prepared using the tartaric acid modified wet chemical sol–gel route. XRD and FESEM techniques confirmed the pristine phase and nanocrystalline property of BFO, Bi0.85Sm0.15FeO3 and BSFCO5 samples. XRD as well as Raman spectra confirmed structural phase transformations from the rhombohedral (pristine BFO) to rhombohedral (Bi0.85Sm0.15FeO3 and Bi0.85Sm0.15Fe0.95Cr0.05O3), in case of Sm-Cr co-doping there is indication of more change of crystal structure than single Sm-doped. Sm-Cr co-doped into BFO could enhance magnetism, more interestingly; M−H loops reveal the highest saturation magnetization value compared to Sm-doped and BFO. An obvious blue shift is noted in the substituted samples as well as the reduction of bandgap compared to pristine BFO. The co-substitution enhanced the photocatalytic degradation activity as compared to Sm-doped and pure BiFeO3.