Heats of sublimation from a polycrystalline mixture of carbon clusters (C60 and C70)
Heats of sublimation from a polycrystalline mixture of carbon clusters (C60 and C70)
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DOI：
10.1021/j100161a003
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发表时间：
1991-04
期刊：
影响因子：
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通讯作者：
C. Pan;M. P. Sampson;Y. Chai;R. Hauge;J. Margrave
中科院分区：
文献类型：
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作者：
C. Pan;M. P. Sampson;Y. Chai;R. Hauge;J. Margrave
在640-800K温度范围内，对C60和C70多晶混合物的平衡蒸气进行了克努森喷雾质谱学测量。从第二定律方法得到，在平均温度707和739K下，C60和C70从多晶C60基质中升华的热的平均值分别为40.1±1.3和43.0±2.2kcal−1。同时指出，为了实现稳定汽化，样品需要在至少170℃的温度下加热12h。这与样品变得更结晶性一致。
Knudsen effusion mass spectrometric measurements of vapors in equilibrium with a polycrystalline mixture of C 60 and C 70 were carried out over the temperature range 640-800 K. From the second-law method, average values obtained for the heats of sublimation of C 60 and C 70 from a polycrystalline C 60 matrix were found to be respectively 40.1±1.3 and 43.0±2.2 kcal mol −1 , at the average temperatures 707 and 739 K. It was also noted that it was necessary to heat treat the samples at temperatures of at least 170°C for greater than 12 h to achieve stable vaporization. This was consistent with the sample becoming more crystalline