Inter-relations of domain orientations and piezoelectric properties in composites based on relaxor-ferroelectric single crystals

ABSTRACT

This paper presents results on a detailed comparative study of 2–2 relaxor-ferroelectric single crystal / polymer composites. Examples of the hydrostatic piezoelectric performance are discussed for 2–2 composites based on [011]-poled Mn-modified 0.26Pb(In_1/2Nb_1/2)·O₃−0.42Pb(Mg_1/3Nb_2/3)O₃−0.32PbTiO₃ single crystals at a molar Mn concentration in the range of 1–5 mol. %. The high piezoelectric activity of these single crystals and rotations of the main crystallographic axes in the single-crystal layers of the composite lead to large values of hydrostatic piezoelectric coefficients , and , squared figure of merit , and electromechanical coupling factor . A rotation mode that leads to a weakening the piezoelectric activity related to the piezoelectric coefficient d₃₂ < 0 is important to achieve composites with a range of large hydrostatic parameters, e.g., ≈ (300–350) pC / N, ∼ 100 mV·m / N, ≈ (21–23) C / m², ∼ (24–30)·10⁻¹² Pa⁻¹, and ≈ 0.30. In contrast to , higher values of ∼ 10⁻¹⁰ Pa⁻¹ are achieved due to the longitudinal piezoelectric effect. The results obtained in this piezoelectric composite system are interpreted by taking into account the orientation of 71° ferroelectric domains in the single-crystal layers and provide a route to form novel high-performance piezoelectric composites.

KEYWORDS:

• Composite
• ferroelectric
• crystallographic orientation
• anisotropy
• hydrostatic piezoelectric response

Acknowledgments

The authors would like to thank Prof. Dr. A.E. Panich, Prof. Dr. I. A. Parinov and Prof. Dr. A.A. Nesterov (Southern Federal University, Rostov-on-Don, Russia), Prof. Dr. P. Bisegna (University of Rome “Tor Vergata”, Italy), and Prof. Dr. M. Lethiecq and Dr. F. Levassort (François Rabelais University, Tours, France) for their continuing interest in the research problems. Special thanks are extended to Prof. Dr. L.N. Korotkov (Voronezh State Technical University, Russia) for his invitation to give a plenary talk on the research results at ISFP-8 (13). Prof. Dr. C. R. Bowen would like to acknowledge funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007–2013) / ERC Grant Agreement no. 320963 on Novel Energy Materials, Engineering Science and Integrated Systems (NEMESIS). In the present paper, the results on the research work No.1597 have been represented within the framework of the base part of the state task No.2014/174 in the scientific activity area at the Southern Federal University (Russia).