Correlation between Volatility of Rare-Earth Metals and Encapsulation of Their Carbides in Carbon Nanocapsules
Correlation between Volatility of Rare-Earth Metals and Encapsulation of Their Carbides in Carbon Nanocapsules
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DOI：
10.1021/j100078a008
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发表时间：
1994-07
期刊：
影响因子：
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通讯作者：
Y. Saito;M. Okuda;Tadanobu Yoshikawa;A. Kasuya;Y. Nishina
中科院分区：
文献类型：
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作者：
Y. Saito;M. Okuda;Tadanobu Yoshikawa;A. Kasuya;Y. Nishina
用电弧法研究了除Pm外的所有稀土元素(Sc，Y和Ln=La，Ce，…，Lu)在多层石墨胶囊中对金属的包覆。电子显微镜和X射线衍射分析表明，大多数稀土金属(Sc、Y、La、Ce、Pr、Nd、Gd、Tb、Dy、Ho、Er和Lu)以碳化物形式包裹，而Sm、Eu和Yb则不是。前者被包裹的金属的蒸汽压明显低于后者。在Tu(TM)的情况下，其蒸气压介于两组之间，只形成了微量的被包裹的碳化物。金属的挥发性与包裹性有明显的相关性，表明金属的挥发性在金属包覆过程中起着重要的作用。参考文献25，图4，表1。
Encapsulation of metals in multilayered graphitic capsules has been studied for all the rare-earth elements (Sc, Y, and Ln = La, Ce, ..., Lu) excluding Pm by using electric arc discharge. Electron microscopy and X-ray diffraction of carbonaceous products revealed that most of rare-earth metals (Sc, Y, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, and Lu) were encapsulated in the form of carbides, but the others, Sm, Eu, and Yb, were not. The metals in the former group that were encapsulated had vapor pressures definitely lower than those in the latter group. In the case of thulium (Tm), whose vapor pressure is intermediate between the two groups, only a trace amount of encapsulated carbide was formed. Correlation of volatility of metals with encapsulation was clearly found, suggesting that the volatility of a metal plays an important role in a process of the metal encapsulation. 25 refs., 4 figs., 1 tab.