This paper summarizes the temperature behavior of various Relaxor-PT piezoelectric single crystals. Owing to the strongly curved morphotropic phase boundary (MPB), the usage temperature is limited by TR-T, the rhombohedral to tetragonal phase transformation occuring at significantly lower temperatures than Tc. Attempts to modify the temperature usage range of PMN-PT and PZN-PT rhombohedral crystals using minor dopant modifications were limited, with little success. Of significant potential are crystals of PYN-PT, with a Tc > 330°C, even though TR-T was nearly half that value at ∼160°C. Lastly, single crystals in the novel Bi(Sc)O 3-PbTiO3 system offer significantly higher Tcs > 400°C, while exhibiting electromechanical coupling coefficients > 90%.
All Science Journal Classification (ASJC) codes
- Acoustics and Ultrasonics