Photoluminescence effects and probing phase transition of Sm3+-doped Ba(Ti0.8Hf0.2)O3-(Ba0.7Ca0.3)TiO3 phosphor prepared by hydrothermal method

Abstract

A series of [(Ba(1-0.3y)Ca0.3y)1-xSmx][Ti(0.8+0.2y)Hf(0.2-0.2y)]O3 (Sm3+-doped (1-y)Ba(Ti0.8Hf0.2)O3-y(Ba0.7Ca0.3)TiO3, abbreviated as Sm3+-doped BCTH, or (1-y)BHT-yBCT:xSm3+, x = 0.0005–0.03, y = 0.2–0.7, y representing the mole fraction of (Ba0.7Ca0.3)TiO3) nano phosphors were prepared by a hydrothermal method. The Sm3+ ions doping amount and triple-point morphotropic phase boundary (TMPB) composition dependent photoluminescence properties were systematically investigated. The hydrothermal synthesized powders present rather pure pseudo-cubic perovskite phase structure at room temperature and locate on the rhombohedral side of MPB. Under the excitation of 409 nm light, the powders exhibit dominant orange-red emission peaks with characteristic emission of the Sm3+ ions at around 564 nm, 596 nm, 644 nm, and 703 nm, relating to the transitions of 4G5/2 → 6H5/2, 6H7/2, 6H9/2 and 6H11/2, respectively. The BHT-0.5BCT:0.005Sm3+ powder exhibits optimal emission in these Sm3+-doped BCTH powders. Furthermore, the phase transition temperature can be characterized by the multi-feature changes of the temperature dependent fluorescence intensity.