Electrical and photoluminescence properties of (Bi_0.5−x/0.94Er_x/0.94Na_0.5)_0.94Ba_0.06TiO₃ lead-free ceramics

In this paper, electrical and photoluminescence properties of the (Bi_0.5−x/0.94Er_x/0.94Na_0.5)_0.94Ba_0.06TiO₃ lead-free ceramics with x ≤ 0.02 were investigated. All ceramics have pure perovskite phase. Lattice distortion induced by the doping of Er³⁺ was observed. The ceramics show average grain sizes around 0.6–1.0 µm. The doped ceramics exhibit decreased dielectric constant, which are still higher than 1200 at room temperature. Curie temperatures of the samples do not fluctuate dramatically with changing the doping amounts, which are around 250 °C. The piezoelectric constant d₃₃ is closely related to the Er³⁺ content. Under an excitation of 487 nm, the ceramics exhibit visible luminescent emissions at 528 nm (green), 548 nm (green), and 670 nm (red).