Improved electrical properties and good thermal luminescent stability of Sm3+-doped Sr1.90Ca0.15Na0.90Nb5O15 multifunctional ceramics

Sm3+ doped Sr1.90Ca0.15Na0.9Nb5O15 (SCNN: xSm(3+)) multifunctional ferroelectric ceramics with pure tetragonal tungsten bronze phase were synthesized via the conventional solid-state reaction method. The dielectric, ferroelectric characteristics and luminescent behaviors were systematically studied. The electrical properties suggested that a moderate Sm3+ doping could enhance the electrical performances. The orange-reddish emission originated from the transition of (4)G(5/2)-> H-6(7/2), (4)G(5/2)-> H-6(5/2) and (4)G(5/2)-> H-6(9/2) was observed under excitation wave of 406 nm. The strongest emission intensities were obtained at the Sm3+ doping content of 0.010. The degree of thermal quenching for the composition with x = 0.010 was relatively lower and the normalized emission intensity continued still 80% from room temperature to 150 degrees C. Besides, the transmittance in visible spectra of the SCNN: xSm(3+) ceramics could be improved obviously, which was up to 50% at the doping amount of 0.010. These results show that the SCNN: xSm(3+) multifunctional ferroelectric niobates have promising potential in electric-optical devices.