Phase switching at low field and large sustainable strain output in domain engineered ferroic crystals



Fundamental shortcomings of ferroelectrics (FEs) are low induced strain and high electric field often required for practical application in actuation, sensors, and acoustics. Although domain engineered FE single crystals deliver an order of magnitude improvement, fatigue remains another drawback in achieving reliable multiple domain switching crucial for memory storage. We demonstrate that under specially compressive stresses FE relaxors exhibit low field induced reversible and sustainable strain associated with FE–FE phase switching and unusual and unexpected lack of fatigue after several millions cycles is believed due to strain accommodation occurring in ferroics. Polarized light microscopy and X-ray diffraction are in a very good agreement with macroscopic observation and phenomenological model confirming proposed transformational path. The phenomena presented in this work are envisioned to be universal in domain engineered ferroics enabling mechanical stress to be used for strain and polarization control of electromechanical energy conversion.