Linear and non-linear optical properties of FeSnO(OH)5 oxyhydroxide perovskite†

Abstract

FeSnO(OH)₅, an oxyhydroxide perovskite also known as jeanbandyite, was prepared by a co-precipitation method and investigated using XRD, SEM, TEM and UV-Vis characterization techniques. The crystal structure of the title compound adopts a cubic system of space group Pn with unit-cell parameters a = 7.6381(5) Å and V = 445.61(5) ų. The optical bandgap energy was estimated from diffuse reflectance data using a modified Kubelka–Munk function. The E_g value for the direct bandgap is 3.00 eV. The Urbach energy (E_U) was determined from the logarithmic absorption coefficient and found to be 1.256 ± 0.006 eV. The dependence of incident photon energy on optical parameters such as refractive index, extinction coefficient, real and imaginary parts of the dielectric function, real and imaginary parts of the complex conductivity, real and imaginary parts of the electrical modulus, dielectric loss and optical conductivity was investigated using UV-Vis spectrophotometer experiments. The obtained values for oscillator energy, dispersion energy, static refractive index, average oscillator strength and average oscillator wavelength were determined using the Wemple–DiDomenico model. The third-order nonlinear optical susceptibility χ⁽³⁾ and nonlinear refractive index (n₂) were calculated from linear optical parameters such as refractive index (n) and susceptibility χ⁽¹⁾.