| 摘要 |
The present invention relates to long decay phosphors comprising rare earth activated strontium aluminates and methods for producing them. The phosphors comprise a matrix of the formula Sr4Al14O25 comprising europium as an activator and a further rare earth element as a co-activator, wherein the molar ratio of Al/Sr in the starting materials is in the range of 3.1 to less than 3.5 and the ratio of Eu/Sr is in the range of 0.0015 to 0.01. The process for the preparation of a phosphor comprises the steps of milling the starting materials for the synthesis of the phosphor, the starting materials comprising a boron compound selected from boric acid, boric oxide or a borate salt in an amount such that the B/Sr molar ratio is between 0.1 and to 0.3, treating the milled composition with heat, grinding the block material which is obtained through the heat treatment, ball-milling the crushed material, sieving the material, and washing the material with an aqueous solution. |
| 主权项 |
1. A process for the preparation of a phosphor comprising a matrix of the formula Sr4Al14O25 comprising europium and dysprosium,
the starting materials including at least an aluminum compound, a strontium compound, a boron compound, an europium compound and a dysprosium compound, whereinthe range of the molar ratio of Al/Sr is 3.1 to 3.45,the range of the molar ratio of Eu/Sr is 0.0025 to 0.0075,the range of the molar ratio of B/Sr is 0.15 to 0.25 andthe range of the molar ratio of Dy/Sr is 0.0075 to 0.015,
the process comprising the steps of providing a homogeneous mixture of the starting materials for the synthesis of the phosphor by milling the starting materials, treating the milled composition with heat, grinding the block material which is obtained through the heat treatment, ball-milling the ground material, and sieving the material. |
