ESR investigation of the oxygen vacancy in pure and Bi2O3-doped zno ceramics

Abstract

ESR measurements of the oxygen vacancy V are performed on undoped ZnO ceramics and on Bi2O3-doped ZnO ceramics additionally heat-treated in reducing atmosphere. The temperature dependences of the relative signal intensity and the line width of the ESR signal are investigated in both the samples. By the measurement of the temperature dependent relative intensity of the ESR signal of the V center the ionization energy of the V center is obtained. An analysis of the temperature dependence of the line width of the ESR signal of the V center in the Bi2O3-doped ZnO ceramics shows that V centers produced by reducing subsequent heat treatment are localized at the boundary layer of the ZnO grains in high local concentrations.