Double-well potentials and structural phase transitions in polyphenyls
Double-well potentials and structural phase transitions in polyphenyls
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多苯中的双阱电势和结构相变
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
C. Zeyen
中科院分区：
文献类型：
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作者：
H. Cailleau;J. Baudour;J. Meinnel;A. Dworkin;F. Moussa;C. Zeyen
在结晶相中，非刚性聚苯分子的构象是由于分子内和分子间相互竞争力之间的微妙平衡。在低温下，相对于苯环之间的扭转角，聚苯晶体经历与非平面构象的稳定化相关的结构相变。一个有趣的特点是这些相变的不同性质：取代联苯和有序无序的对三联苯。为了说明这一点，我们考虑了以下特点：在高温阶段的热运动，流体静压力的影响，在对-三联苯的相变，过渡热容，观察到的对-三联苯的波动的临界减慢和在联苯中存在的无公度相。
In their crystalilne phases, the conformation of non-rigid polyphenyl molecules results from a delicate balance between competing intramolecular and intermolecular forces. At low temperature, the polyphenyl crystals undergo structural phase transitions associated with stablization of a non-planar conformation, with respect to a torsional angle between the phenyl rings. An interesting feature is the different natures of these phase transitions: displacive in biphenyl and order–disorder in p-terphenyl. In order to illustrate this point we consider the following features: the thermal motion in the high-temperature phases, the influence of hydrostatic pressure on the phase transition in p-terphenyl, the transitional heat capacities, the observation of the critical slowing down of fluctuations in p-terphenyl and the existence of incommensurate phases in biphenyl.