Lead iron tungstate, Pb(Fe2/3Wy3)03 (PFW), exhibits typical ferroelectric relaxor characteristics around 185K (lOkHz). Besides the ferroelectric relaxation, a second dielectric relaxation was observed in undoped, La’^^ and Mn^+ doped PFW ceramics in the temperature range of 200-350K. The intensity of dielectric permittivity and loss factor peaks was found to be strongly related to the resistivity: it increases with the increase in the resistivity. The relaxation activation energy is also in the same range of the condution activation energy for each sample. The relaxation mechanism is discussed and a space charge polarization is suggested to explain the observed dielectric relaxation.
Relación estructura-propiedades y estudios espectroscópicos de vidrios de óxido BaO-B2O3 que contienen ZnO para aplicaciones ópticas
En el presente trabajo se prepararon muestras de vidrios de óxido de borato de bario que contienen diferentes proporciones molares de ZnO,