Actas de congresos
Study of the influence of Eu3+ ions in the bandgap of K2NdNb5O15Nanopowders
Materials Science Forum, v. 820, p. 378-383.
Universidade Estadual Paulista (UNESP)
Ferroelectric semiconductors oxides with tetragonal tungsten bronze TTB-type structure doped with rare earth ions have been investigated in recent years due their promising optical properties. K2Nd(1-x)EuxNb5O15 nanopowders, where x = 0, 0. 0025, 0. 025, 0. 05 and 0. 1 were synthesized by the modified polyol method and characterized by X-ray diffraction and diffuse reflectance spectroscopy UV-Vis. Single phase and crystalline powders of tetragonal symmetry with non-centrosymmetric space group P4bm were obtained. The diffuse reflectance spectra were similar to the profile of a semiconductor material with the presence of thin transitions of Eu3+ in europium-doped K2NdNb5O15, as well as the transitions of Nd3+. The method of Kubelka-Munk was used for the estimation of bandgap energy. The values around 3. 7 eV showed small variation with the concentration of Eu3+ ions in the K2NdNb5O15 host structure. The transitions were identified as direct ones type.