The temperature behavior of various relaxor-PT piezoelectric single crystals was investigated. Owing to a strongly curved morphotropic phase boundary, the usage temperature of these perovskite single crystals is limited by T R-T - the rhombohedral to tetragonal phase transformation temperature - which occurs at significantly lower temperatures than the Curie temperature T C. Attempts to modify the temperature usage range of Pb(Zn 1/3Nb 2/3)O 3-PbTiO 3 (PZNT) and Pb(Mg 1/3Nb 2/3)O 3-PbTiO 3 (PMNT) rhombohedral crystals (T c ∼ 150-170°C, T R-T ∼ 60-120°C) using minor dopant modifications were limited, with little success. Of significant potential are crystals near the morphotropic phase boundary in the Pb(Yb 1/2 Nb 1/2)O 3-PbTiO 3 (PYNT) system, with a T c > 330°C, even though T R-T was found to be only half that value at ∼160°C. Single crystals in the novel BiScO 3-PbTiO 3 system offer significantly higher T cs > 400°C, while exhibiting electromechanical coupling coefficients k 33 > 90% being nearly constant till the T R-T temperature around 350°C, which greatly increases the temperature range for transducer applications.
|Original language||English (US)|
|Number of pages||5|
|Journal||IEEE transactions on ultrasonics, ferroelectrics, and frequency control|
|State||Published - Apr 2005|
All Science Journal Classification (ASJC) codes
- Acoustics and Ultrasonics
- Electrical and Electronic Engineering