Structural and optical investigations of Nd and Cu doped BaTiO3 prepared by solid state reaction

Abstract

In this work, we have prepared some doped BaTiO3 powders with the aim to study the change of physical properties and some behaviors to be closely sensitive to the nature of the doping elements. The main advantage of this material is the possibility of replacing subparts of the Ba ions that improve their physical properties. In particular, the optical properties of the Nd and Cu doped sample prepared by solid-state methods and (x = 0.00, 0.05, 0.10, 0.15& 0.20) ceramics were found to be strongly correlated with the doping rate of the barium ions. Precursor powders with stoichiometric amounts were mixed thoroughly and hand-crushed in an agate mortar for 2–3 h for samples, and then dried and calcined at 850 and 1100 °C for 2 and 4 h. X-Ray diffraction technique was used to study the structural properties of the produced phases. By Scherrer method calculation, It has been found that grain size increases as the doping rate increases for Nd ions for the cubic structure and for Cu ions for the tetragonal structure. For all of them, sizes values are between 27 and 31 nm. With scanning electronic microscopy SEM, some doped samples exhibit bi-dimensional nano-sheets. The Raman spectroscopy technique has been used to study the local behavior, we conclude that there is bands connected to cubic and tetragonal phase for Nd-doped BT. As for Cu-doped BT bands connected to tetragonal only. Optical properties of prepared samples were investigated by measuring the transmittance spectra range is between 200 and 900 nanometers. The Tauc curves are carried out to determine the band gap energy to raise in values from 3.17 eV to 3.2 eV for Nd dopant ions, and to decrease in values of the gap energy from 3.17 eV to 1.9 eV in Cu ions. The refractive index at wavelength 400 nm was also evaluated and it was found that Nd-doped increases from 5.45 to 6.32 and Cu-doped decreases from 5.45 to 1.82.