Comparative investigation and mechanistic analysis of textured PMN-30PT ceramics using BaTiO₃ and PbTiO₃ templates

Homogeneous PbTiO₃ (PT) templates are considered an ideal choice for textured lead-based piezoceramics. In order to further investigate the texture mechanism and topological microcrystal conversion of PT templates, a comparative investigation and mechanistic analysis were conducted on Pb(Mg_1/3Nb_2/3)O₃-30PbTiO₃ (PMN-30PT) textured ceramics prepared using the template grain growth (TGG) technique, with 〈001〉 oriented BaTiO₃ (BT) and PbTiO₃ (PT) as templates. The results show that the use of BT templates resulted in a textured ceramic with a Logtering factor of 91%, a piezoelectric coefficient of 824 pC N^-1, and parallel striped domains, compared to 11%, 534 pC N^-1, and fingerprint-like domains with PT templates. However, the PT templates have poor morphology and structural instability. This is due to the chaotic substitution of Bi³⁺ with Pb²⁺ and interlayer detachment at the 4a position during the topochemical conversion process, which results in the formation of PT nanosheets. At the same time, the residues of Bi³⁺ lead to the formation of a more complex Aurivillius structure and allow PT templates to be embedded in this structure. Additionally, the lower formation energy, the increased lattice parameter difference, and the lower melting point of PT templates make them more susceptible to diffusion into the matrix grain. Based on this comprehensive analysis, it can be concluded that achieving textured piezoceramics with PT templates is a challenging task.