ゼロ次脱離
相転移に関連して起こる反応速度の異常
1988 年 9 巻 2 号 p. 139-145
詳細
1988 年 9 巻 2 号 p. 139-145
Abnormal zero-order desorption spectrum (ZODS), which shows constant desorption rate even when the adsorbed amount is decreasing, has been reported for several systems in thermal- or isothermal-desorption measurements. These ZODSs are observed coincidentally with the appearance of liquid-gas phase coexistence region in adsorbate system. Recently, another type of ZODS was observed in the phase-coexistence region between adsorbate-induced-reconstructed- and normallyadsorbed phases of H/Ni (110) system. Examples of these experimentally observed ZODS are summarized. And our interpretation of ZODS is proposed, which is derived on the naive basis of transition state theory and the lattice-gas statistics. The derived rate is known to be different from the conventionally used ones. Therefore, the latter conventional rates are examined and are shown to fail in the explanation of ZODS even qualitatively.
