Interlayer cohesive energy of graphite from thermal desorption of polyaromatic hydrocarbons
Interlayer cohesive energy of graphite from thermal desorption of polyaromatic hydrocarbons
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DOI：
10.1103/physrevb.69.155406
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发表时间：
2004-04-01
影响因子：
3.7
通讯作者：
Hertel, T
中科院分区：
文献类型：
--
作者：
Zacharia, R;Ulbricht, H;Hertel, T
利用热脱附光谱研究了多环芳烃与石墨基面的相互作用。苯，萘，coronene，和ovalene在亚单层覆盖率的解吸动力学产生的活化能为0.50 eV，0.85 eV，1.40 eV，和2.1 eV，分别。苯和萘遵循简单的一级脱附动力学，而晕苯和卵苯表现出分数级动力学，由于二维吸附物岛的稳定性，脱附温度。根据Falconer-Mastern（等温解吸）分析和Antoine对蒸气压数据的拟合，发现指前频率因子在10（14）-10（21）s（-1）范围内。PAH的每个碳原子的结合能为52+/-5 meV，可以用石墨的层间结合能来确定。石墨的裂解能为61+/-5 meV/atom，这比以前报道的实验值大得多。
We have studied the interaction of polyaromatic hydrocarbons (PAHs) with the basal plane of graphite using thermal desorption spectroscopy. Desorption kinetics of benzene, naphthalene, coronene, and ovalene at submonolayer coverages yield activation energies of 0.50 eV, 0.85 eV, 1.40 eV, and 2.1 eV, respectively. Benzene and naphthalene follow simple first order desorption kinetics while coronene and ovalene exhibit fractional order kinetics owing to the stability of two-dimensional adsorbate islands up to the desorption temperature. Preexponential frequency factors are found to be in the range 10(14)-10(21) s(-1) as obtained from both Falconer-Madix (isothermal desorption) analysis and Antoine's fit to vapor pressure data. The resulting binding energy per carbon atom of the PAH is 52+/-5 meV and can be identified with the interlayer cohesive energy of graphite. The resulting cleavage energy of graphite is 61+/-5 meV/atom, which is considerably larger than previously reported experimental values.