Unipolar Fatigue Behavior of BCTZ Lead‐Free Piezoelectric Ceramics |
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| Authors: | Yichi Zhang Julia Glaum Matthias C. Ehmke Keith J. Bowman John E. Blendell Mark J. Hoffman |
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| Affiliation: | 1. School of Materials Science and Engineering, UNSW Australia, NSW, Australia;2. School of Materials Engineering, Purdue University, West Lafayette, Indiana;3. Mechanical, Materials & Aerospace Engineering, Illinois Institute of Technology, Chicago, Illinois |
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| Abstract: | (Ba,Ca)(Ti,Zr)O3 lead‐free piezoelectric ceramics have been considered to be one of the most potential lead‐free alternatives for PZT in the room‐temperature range. The stability of the piezoelectric performance during unipolar cycling is investigated in this study. It is found that the unipolar fatigue behavior is similar to soft PZT. Developments of bias field, offset polarization, asymmetry in strain, and dielectric hysteresis loops are observed during bipolar measurements. The changes are mainly contributed to the migration of charge carriers to the grain boundaries driven by the unscreened depolarization field. Redistribution of the accumulated charge carriers by bipolar electric cycling or thermal annealing can significantly recover the unipolar fatigued state. The unipolar strain response stabilized after 1000 cycles at 0.053% for an electric field of 0.6 kV/mm (d33*= 883 pm/V), which is a good characteristic for actuator applications. |
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