Polarization fatigue in Pb(Zn1/3Nb2/3)O3–PbTiO3 ferroelectric single crystals

Abstract

Pb(Zn 1/3 Nb 2/3 ) O 3 –PbTiO 3 (PZN–PT) single crystal ferroelectrics have been studied to determine the relative rates of polarization fatigue. It was recently found that ferroelectrics with the rhombohedral phase in the PZN–PT solid solution have essentially no polarization fatigue in the [001]C directions (all of the orientations in this article will be given in terms of the prototype cubic (m3m) axes, denoted by the subscript C). In this study, we expand upon this observation to correlate fatigue rates more completely with respect to composition, orientation, temperature, and electric field strength. It is inferred that an engineered domain state in relaxor based ferroelectric crystals with the spontaneous polarization inclined to the normal of the electrode is associated with negligible or no fatigue at room temperature. However, if thermal history, temperature, or field strength induces a phase transition that produces a polarization parallel to the normal of electrode, these orientations fatigue. The relative fatigue rates are also studied as a function of temperature. In directions, such as [111]C in the ferroelectric rhombohedral phase, the polarization fatigues at room temperature, but as temperature is increased the fatigue rate systematically decreases. This is explained in terms of a thermally activated process that limits the net fatigue rate of ferroelectrics. In summary, this article gives information on the polarization states and orientation that control fatigue in ferroelectric crystals with a relaxor end member.