Shuang Gao (Darmstadt / DE), Changhao Zhao (Darmstadt / DE), Matthias Bohnen (Darmstadt / DE), Ralf Müller (Darmstadt / DE), Jürgen Rödel (Darmstadt / DE), Hans-Joachim Kleebe (Darmstadt / DE)
Abstract text (incl. figure legends and references)
Ferroelectric hardening is an absolute requirement for potential applications of piezoceramics in high-power devices [1,2]. The state-of-the-art researches [3,4] demonstrate that ferroelectric hardening by pinning domain walls with precipitates introduced during processing is feasible, akin to precipitation hardening in metals [5]. With the precipitation of plate-like LiNbO3 in Li-doped NaNbO3 piezoceramics, ferroelectric hardening was achieved, exhibiting an enhanced mechanical quality factor (Qm). The specific morphology and corresponding orientation of the LiNbO3 platelets, exhibiting {110}PC habit planes, were characterized by transmission electron microscopy (TEM). The experimentally revealed crystallographic structures and strain incompatibility were found to correlate well with the thermodynamic simulation of the minimum-energy aspect ratio. In particular, the topology of the precipitate-domain wall assembly was clarified, revealing a full pinning on the domain walls by the incorporated plate-like precipitates. The revealed topology provides a fundamental basis for future optimization strategies for platelet hardening in new lead-free piezoceramics for high-power applications.
References:
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