Artículos de revistas
Phase stability and properties of Bi6Te2O13+delta (delta=0 or 2)
Fecha
2021-03-15Registro en:
Physica B-condensed Matter. Amsterdam: Elsevier, v. 605, 6 p., 2021.
0921-4526
10.1016/j.physb.2020.412780
WOS:000618825400001
Autor
Universidade Federal de Goiás (UFG)
Universidade Estadual Paulista (Unesp)
Institución
Resumen
The crystalline Bi6Te2O15 and Bi6Te2O13 phases with orthorhombic and cubic symmetries, respectively, were synthesized by solid-state reaction synthesis. A study of the thermal stability of both phases was carried out, being verified that the high temperature cubic phase can be kept at room temperature in a metastable condition during long time. The Raman scattering spectrum, optical reflectivity and photoluminescence emission of these phases were measured for the first time. The optical band gaps E-g = 3.29eV, for the orthorhombic phase, and E-g = 3.08eV, for the cubic phase, were calculated from the reflectivity spectra. Using the brick-layer model the electrical conductivity of a dense ceramic of Bi6Te2O15 was measured, taking in account the grain and grain-boundary effects.