Piezoelectric Er3+-doped (Ba1-xCax)(Sn0.06Ti0.94)O3 ceramic: Photoluminescence sensitive to morphotropic phase boundary

• The Er3+ doped (Ba1-xCax)(Sn0.06Ti0.94)O3 ceramics were sintered.
• High sensitivity of photoluminescent and ferro-/piezoelectric properties on phase transition was found.
• Photoluminescence indicating piezoelectric’s morphotropic phase boundary was developed.

The 0.5 mol% Er3+-doped piezoelectric (Ba1-xCax)(Sn0.06Ti0.94)O3 lead-free ceramics were prepared via a conventional solid-state sintering process. The confirmed morphotropic phase boundary of this material locates at x = 0.03 through measuring x dependence on dielectric and ferro-/piezoelectric performances. It was found that photoluminescence of Er3+-doped (Ba1-xCax)(Sn0.06Ti0.94)O3 ceramics is sensitive to the structural phase transition. With the increase of x from 0.01 to 0.06, the photoluminescence peak intensity at 550 nm first increases and then decreases, giving to the optimal value at x = 0.03. The typical characteristic, photoluminescence sensitive to morphotropic phase boundary, can be used to develop a non-contact and sensitive way to indicate phase transition region of rare-earth doped lead-free piezoelectric ceramics.