Evolution of the tetragonal to rhombohedral transition in (1 â‹TM x)(Bi1/2Na1/2)TiO3 â‹TM xBaTiO3 (x ⛤ 7%)

1 − x)(Bi1/2Na1/2)TiO3 − xBaTiO3 has been the most studied Pb-free piezoelectric material in the last decade; however, puzzles still remain about its phase transitions, especially around the important morphotropic phase boundary (MPB). By introducing the strain glass transition concept from the ferroelastic field, it was found that the phase transition from tetragonal (T, P4bm) to rhombohedral (R, R3c) was affected by a strain glass transition at higher temperature for x ≥ 4%. In these compositions, the T–R transition was delayed or even totally suppressed and displayed huge thermal hysteresis upon cooling and heating. Also, isothermal phase transitions were predicted and realized successfully in the crossover region, where the interaction between the T–R transition and the strain glass transition was strong. Our results revealed the strain glass nature in compositions around the MPB in this important material, and also provide new clues for understanding the transition complexity in other (Bi1/2Na1/2)TiO3-based Pb-free piezoelectric materials. Disciplines Materials Science and Engineering Comments This article is from Science and Technology of Advanced Materials 14 (2013): 035008, doi:10.1088/1468-6996/ 14/3/035008. Rights Content from this work may be used under the terms of the Creative Commons AttributionNonCommercial-ShareAlike 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/mse_pubs/32 This content has been downloaded from IOPscience. Please scroll down to see the full text.