Investigation of structural and optical properties of SmCrO3 orthochromite compound prepared via sol–gel process

Abstract

The SmCrO₃ compound was synthesized using the sol–gel method. Structural analysis via X-ray diffraction confirmed that the compound is pure, monophasic, and crystallizes in an orthorhombic structure with a Pnma space group. Optical properties were examined using infrared (IR) and UV–Vis absorption spectroscopy. The IR spectrum showed distinct absorption peaks that could be attributed to the O–Cr–O and Cr–O vibrations. The Tauc model applied to UV–Vis data estimated the direct optical band gap to be 3.3eV. Additional optical parameters, including Urbach energy, optical extinction coefficient, and refractive index, were calculated from absorbance measurements. Furthermore, the penetration depth, optical conductivity, and dispersion energy parameters were analyzed as a function of the incident photon's wavelength. The UV–Vis absorbance spectrum, attributed to the 3d–3d transitions of Cr³⁺ ions and the 4f–4f transitions of Sm³⁺ ions, provided insights into the electronic structure of the SmCrO₃ sample. A Tanabe-Sugano diagram was constructed based on a theoretical Racah analysis. These findings suggest that the synthesized sample has strong potential for applications in optoelectronic devices.