Tuning the ferroelectric, dielectric and photoluminescence properties of 0.88(Na0.5Bi0.5)TiO3-0.12BaTiO3 ceramics by Sm ion doping

Solid solutions of the lead-free 0.88( Na 0 . 5 ${\text{Na}}_{0.5}$ Bi 0 . 5 ) ${\text{Bi}}_{0.5})$ TiO 3 -0.12( Ba 1 − x ${\text{Ba}}_{1-x}$ Sm x ) ${\text{Sm}}_x)$ TiO 3 (NBT-BT: x $x$ Sm) ferroelectric ceramics were synthesized by solid state reaction. The doping of Sm promotes the structure of the ceramics to transform toward morphotropic phase boundary, and it decreases the grain size of the ceramics. With the increase of Sm content, the ferroelectric properties are improved gradually, where the ferroelectric polarization increases and the coercive field decreases. Sm doping induces a dielectric anomaly with obvious frequency dispersion at a low temperature, exhibiting the transition from the ferroelectric to relaxor state. Moreover, the photoluminescence spectra of NBT-BT: x $x$ Sm ceramics exhibit a strong orange emission upon blue light excitation of the 400 $$ nm to 500 $$ nm. The emission intensities are strongly dependent on the Sm doping concentration, which reached the optimal value as the doping concentration is 0.7%. These results suggest that the NBT-BT: x $x$ Sm ceramics may have significant technological promise in novel multifunctional devices.