【摘要】 用穆斯堡尔谱研究了Eu₂O₃在不同载体表面上的分散度。随着铕含量的变化引起的穆斯堡尔参数的差别表明了Eu₂O₃与不同载体之间作用上的差别。在γ-Al₂O₃ 表面上,当Eu含量增加时,用质异能位移增加,逐渐接近于体相Eu₂O₃相应值,说明在逐步形成Eu₂O₃晶相。与此不同,在两种SiO₂载体表面上,同质异能位移基本不变,表明Eu₂O₃在铺满单层后,倾向于按层铺排,而不是形成晶相,由穆斯堡尔谱所得结论与X射线衍射结果符合。更多还原

【Abstract】 Mossbauer spectroseopy has been used to study the dispersity of Eu2O3 on the surface of different supports. Changes in Mossbauer parameters as a function of the europium content reveal the difference of the interaction between Bu2O3 and the support. On the surface of γ-Al2O3, the Mossbauer isome shift progressively increases toward to that of bulk Eu2O3 with increasing metal loading, suggesting that the crystal phase of Eu2O3 forms gradually. In contrast, on the surfaces of two types of SiO2 the isomer shifts do not change with changing the metal loading in the range of our study. This suggests that Eus03 tends to spread out on the surface as a second layer over monola-yer dispersion. The conclusion obtained by Mossbauer spectroseopy is in agreement with that obtained by X-ray diffraction.更多还原