• Abstract talk
  • MS7.006

Precipitate-domain wall topologies in hardened Li-doped NaNbO3


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spectrum A


Ceramics and composites


  • MS 2: Metals and alloys
  • MS 7: Ceramics and composites


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.


[1] K.H. Hardtl, Electrical and mechanical losses in ferroelectric ceramics, Ceram. Int. 8 (1982) 121-127.

[2] K. Uchino, J.H. Zheng, Y.H. Chen, X.H. Du, J. Ryu, Y. Gao, S. Ural, S. Priya, S. Hirose, Loss mechanisms and high power piezoelectrics, J. Mater. Sci. 41 (2006) 217-228.

[3] C.H. Zhao, S. Gao, T.N. Yang, M. Scherer, J. Schultheiß, D. Meier, X.L. Tan, H.J. Kleebe, L.Q. Chen, J. Koruza, J. Rödel, Precipitation hardening in ferroelectric ceramics, Adv Mater. 33 (2021) 2102421.

[4] C.H. Zhao, S. Gao, H.J. Kleebe, X.L. Tan, J. Koruza, J. Rödel, Coherent precipitates with strong domain wall pinning in alkaline niobate ferroelectrics, Adv. Mater. Accepted, (2022).

[5] A.J. Ardell, Precipitation hardening, Metall. Mater. Trans. A 16A (1985) 2131-2165.

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