摘要： In this work, we made five samples of SrAl₂O₄: Eu²⁺, Dy³⁺, the α phase and β phase SrAl₂O₄:Eu²⁺,Dy³⁺ powder and pellet samples, and α phase single crystal. We have measured the emission spectra of all the samples. All the emission peaks are around 520 nm, which correspond to the transition from 4f⁶5d¹(²E_g) to 4f⁷(⁸S_7/2) of Eu²⁺ in SrAl₂O₄ host. The intensity of emission of the β phase is stronger than that of the α phase. We believe that it is because the Eu²⁺ ions have occupied the two types of sites in the α phase SrAl₂O₄ host and the lifetime of the transition of Eu²⁺ in the A site is longer than that in the B site. This result also proves that the β phase of the material is brighter than the α phase. In addition, the β phase can be achieved by quenching technique.

Abstract: In this work, we made five samples of SrAl₂O₄: Eu²⁺, Dy³⁺, the $\alpha$ phase and $\beta$ phase SrAl₂O₄:Eu²⁺,Dy³⁺ powder and pellet samples, and $\alpha$ phase single crystal. We have measured the emission spectra of all the samples. All the emission peaks are around 520 nm, which correspond to the transition from 4f⁶5d¹(²E_g) to 4f⁷(⁸S_7/2) of Eu²⁺ in SrAl₂O₄ host. The intensity of emission of the $\beta$ phase is stronger than that of the $\alpha$ phase. We believe that it is because the Eu²⁺ ions have occupied the two types of sites in the $\alpha$  phase SrAl₂O₄ host and the lifetime of the transition of Eu²⁺ in the A site is longer than that in the B site. This result also proves that the $\beta$ phase of the material is brighter than the $\alpha$  phase. In addition, the $\beta$ phase can be achieved by quenching technique.

中图分类号:  (Crystal and ligand fields)

• 71.70.Ch

78.55.Hx (Other solid inorganic materials) 81.40.Gh (Other heat and thermomechanical treatments)