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

A series of [(Ba (1-0.3y) Ca 0.3y ) 1-x Sm x ][Ti (0.8+0.2y) Hf (0.2-0.2y) ]O 3 (Sm 3+ -doped (1-y)Ba(Ti 0.8 Hf 0.2 )O 3 -y(Ba 0.7 Ca 0.3 )TiO 3 , abbreviated as Sm 3+ -doped BCTH, or (1-y)BHT-yBCT:xSm 3+ , x = 0.0005–0.03, y = 0.2–0.7, y representing the mole fraction of (Ba 0.7 Ca 0.3 )TiO 3 ) nano phosphors were prepared by a hydrothermal method . The Sm 3+ 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 Sm 3+ ions at around 564 nm, 596 nm, 644 nm, and 703 nm, relating to the transitions of 4 G 5/2  →  6 H 5/2 , 6 H 7/2 , 6 H 9/2 and 6 H 11/2 , respectively. The BHT-0.5BCT:0.005Sm 3+ powder exhibits optimal emission in these Sm 3+ -doped BCTH powders. Furthermore, the phase transition temperature can be characterized by the multi-feature changes of the temperature dependent fluorescence intensity.