Investigation studies of structural, electrical, dielectric, and optical of DyTi0.5 Mn0.5O3 multiferroic for optoelectronics applications

Abstract

In the present communication, the Ti-doped DyMnO3, i.e., DyTi0.5Mn0.5O3 (DTMO) perovskite has been synthesized by the conventional solid-state reaction technique, and emphasis has been made to observe the variations on structural, electrical, dielectric, and optical properties of the prepared ceramic. The XRD patterns confirm that our compound crystallizes in the orthorhombic system with the Pmmm space group with a crystallite size of 53 nm. The FTIR spectrum highlights a set of absorption peaks that can be attributed to Mn–O–Mn and Mn–O vibrations. The electrical and dielectric proprieties were characterized by impedance spectroscopy as a function of frequency temperature. The total conductivity obeying Jonscher’s universal power law indicates that our material exhibits a semiconductor trend and the conduction mechanism is ensured by NSPT model. The activation energy deduced from the study of continuous conductivity noted Edc is equal to 0.394 eV. The behaviors of permittivity and loss factor have been investigated using Maxwell–Wagner’s model of interfacial polarization. The contribution of grains and grain boundaries effect in the conduction mechanism was confirmed by the Nyquist plots. The latter was fitted with an appropriate equivalent circuit. The curves of imaginary parts of impedance (Z″) and modulus (M″) show a dielectric-relaxation phenomenon in the sample. Thermodynamic parameters; the enthalpy and the entropy have been determined. The optical properties were carried by UV–Vis–NIR spectroscopy. The diffused reflectance spectra (DRS) reveal that our material has a good optical absorption behavior in the UV region. The direct bandgap energy Eg = 4.8 eV of the studied sample is estimated using the UV/visible DRS data using the Kubelka–Munk method and Marotti’s approach. Furthermore, the Urbach–Martienssen model is used to calculate the Urbach energy (EU) which is evaluated at 0.632 eV showing a disorder in this compound. The refractive index, the extinction coefficient, the skin depth and the optical conductivity as a function of the wavelength of the incident photon were determined and discussed.