Search

The dc electric-field dependence of the dielectric properties of cadmium niobate Cd2Nb2O7 single crystals is studied, and characteristics of the dielectric behavior of Cd2Nb2O7 under dc bias are revealed. The temperature (Tm) where the dielectric relaxation mode occurs is independent of dc bias levels, while its intensity is greatly suppressed and finally eliminated with increasing dc bias from 0 to 15 kV/cm. The observed dielectric relaxation features of Cd2Nb2O7 can be attributed to “dielectric relaxor” behavior, rather than “ferroelectric relaxor” behavior previously designated in literature. The physical nature of the dielectric relaxor behavior is briefly discussed. [ABSTRACT FROM AUTHOR]

The direct-current (dc) electric-field dependence of dielectric constant around paraelectric-ferroelectric transition in Cd[sub 2]Nb[sub 2]O[sub 7] has been studied. The results show significant suppression of the dielectric constant by the application of dc bias. The electric-field dependence of the dielectric constant at the temperature around paraelectric-ferroelectric phase transition can be well described by the modified Devenshire relation including a cluster term, i.e., ε(E)=ε[sub 1]-ε[sub 2]E[sup 2]+ε[sub 3]E[sup 4]+(Px/ε[sub 0])[cosh(Ex)][sup -2]. The fit parameters indicate that the polar-cluster carries polarization P=∼0.5-2.5 mC/m[sup 2] with the cluster size of L=∼11-15 nm. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]