Polarization Fatigue in Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 Single Crystals

摘要

Electric fatigue tests have been conducted on pure and manganese modified Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals along different crystallographic directions. Polarization degradation was observed to suddenly occur above 50–100 bipolar cycles in <110> oriented samples, while <001> oriented samples exhibited almost fatigue free characteristics. The fatigue behavior was investigated as a function of orientation, magnitude of the electric field and manganese dopant. It was found that <001> oriented PIN-PMN-PT crystals were fatigue free, due to its small domain size, being on the order of 1µm. The <110> direction exhibited a strong electrical fatigue behavior due to mechanical degradation. Micro/macro cracks were developed in fatigued <110> oriented single crystals. Fatigue and cracks were the results of strong anisotropic piezoelectric stress and non-180° domain switching, which completely locked the non-180° domains. Furthermore, manganese modified PIN-PMN-PT crystals were found to show improved fatigue behavior due to its enhanced coercive field.