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采用高温固相法,在还原气氛下制备出Al2O3/蒙脱土:Eu2+光致发光材料。研究了原料配比、烧结温度、保温时间以及激活剂Eu2+的含量对发光性能的影响。实验结果表明:加入蒙脱土后,所制备的样品仍保持Al2O3的架状结构,晶格常数发生变化,晶体产生畸变,使得Eu2+更容易进入到晶格中。荧光光谱分析显示,发射光谱是两个宽峰组成,对应于Eu2+的4f65d→4f7(8S7/2)宽带允许跃迁。发光机制分析认为,宽峰结构由Eu0.92[Al1.76Si2.24O8]新相产生,生成的新相增加了Eu2+的取代格位,形成新的发光中心。因此Eu2+不仅取代了Al2O3八面体中Al的格位,而且取代了蒙脱土层间所吸附的阳离子格位,使样品发光强度提高了220%。
High temperature solid phase method was used to prepare Al2O3 / montmorillonite: Eu2 + photoluminescence material under the reducing atmosphere. The effects of raw material ratio, sintering temperature, holding time and the content of activator Eu2 + on the luminescent properties were studied. The experimental results show that after the addition of montmorillonite, the prepared sample still retains the framework structure of Al2O3, the lattice constant changes, and the crystal is distorted so that Eu2 + can enter into the crystal lattice more easily. Fluorescence spectrum analysis shows that the emission spectrum is composed of two broad peaks corresponding to the 4f65d → 4f7 (8S7 / 2) broadband allowable transition of Eu2 +. The analysis of the light-emitting mechanism shows that the broad-peaked structure is formed by a new phase of Eu0.92 [Al1.76Si2.24O8], and the new phase is added with the replacement of Eu2 + to form a new luminescent center. Therefore, Eu2 + not only replaced the lattice sites of Al in the octahedron of Al2O3, but also replaced the cation lattice sites adsorbed in the montmorillonite layer, which increased the luminous intensity of the sample by 220%.