Rates of Electron Emission from Negatively Charged, Impact-Heated Fullerenes
Rates of Electron Emission from Negatively Charged, Impact-Heated Fullerenes
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带负电、冲击加热的富勒烯的电子发射率
DOI：
10.1126/science.260.5108.652
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发表时间：
1993
期刊：
影响因子：
56.9
通讯作者：
R. Whetten
中科院分区：
文献类型：
--
作者：
C. Yeretzian;K. Hansen;R. Whetten
电子的热辐射通常被认为是宏观凝聚态物质独有的特性。某些小型金属团簇以及硅和碳团簇也会发生慢电子发射，但这一过程的性质尚未确定。通过对带负电荷的富勒烯在多种尺寸和较宽的连续能量范围内的大量实时测量，获得并分析了电子发射率。这些结果证实，延迟电子发射是一个简单的激活过程，它强烈依赖于内部能量和星团的大小，并且它具有一个共同的潜在机制，独立于大小。然而，推导出的阿伦尼乌斯形式与用于体表面的发射速率理论不一致。这些结果允许对这个新观察到的电子发射过程的正确微观描述的问题进行评估。
Thermal emission of electrons is ordinarily considered to be exclusively a property of macroscopic condensed matter. Slow electron emission occurs for certain small metal clusters as well as for silicon and carbon clusters, but the nature of this process has not been established. Electron emission rates have been obtained and analyzed from extensive real-time measurements on negatively charged fullerenes for several sizes and over a wide, continuous range of energies. These results confirm that delayed electron emission is a simple activated process that depends strongly on the internal energy and size of the cluster and that it has a common underlying mechanism, independent of size. However, the Arrhenius form deduced is inconsistent with the emission rate theory used for bulk surfaces. These results allow the question of the correct microscopic description of this newly observed electron emission process to be assessed.