三斜相GdBO_3:Eu的溶胶 凝胶法制备及其格位选择激发下的光谱(英文)

Preparation and Site Selective Luminescence of Eu^(3+) in Triclinic GdBO_3

用溶胶 凝胶法合成了具有三斜结构的低温相GdBO3,并与用常规的固相反应制备的类球方解石结构的样品作了比较。在高于 1 0 0 0℃时发生了三斜相向常规相的相变。三斜相GdBO3:Eu的荧光光谱表明阳离子在基质晶格中占据了两种格位 ,用A和B来分别标明。选择激发A、B格位上Eu3+ ,结果揭示了GdBO3结构上的变化和Eu3+ 之间的能量传递过程。在较高的Eu3+ 掺杂浓度时 ,两个格位均有较强的发光 ;在低温和低浓度条件下 ,得到了可分辨的相应于不同格位的发光 ,并观察到了两个格位间不同几率的能量相互传递。

Lowtemperature phase of GdBO 3 with triclinic form was prepared by SolGel process, while only pseudovaterite form could be obtained from the conventional solid state reaction. The triclinic form will change to pseudovaterite structure when being heated at higher than 1000℃. Luminescence of the triclinic GdBO 3:Eu indicated the existence of two different sites of the cations in the host, which were denoted as A and B in the work. Then site selective luminescence of the sample was investigated. The influences of concentration and temperature on the luminescence properties were reported. For high Eu 3+ concentration, a very strong interaction took place between the dopants. Emissions from the two sites were both strong and could not be separated. At low temperature and with a low concentration, selective luminescence from the two sites was obtained. Different energy transfer rates of site A→B and B→A were also observed.