Observation of the effects of critical phenomena in paraterphenyl on quasielastic incoherent neutron spectra. II
Observation of the effects of critical phenomena in paraterphenyl on quasielastic incoherent neutron spectra. II
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观察对三联苯中的临界现象对准弹性非相干中子谱的影响。
DOI：
10.1088/0022-3719/17/31/007
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
R. Lechner
中科院分区：
文献类型：
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作者：
B. Toudic;R. Lechner
通过准弹性非相干中子散射研究了对三联苯 (C18H14) 的有序-无序相变。远离转变点时，测得的准弹性光谱揭示了分子取向几乎随机无序的动力学 (T>Tc) 或对应于取向长程有序的近静态行为，但仍包括少量动态无序 (T<Tc)。然而，在 Tc 附近，准弹性非相干中子谱明显受到取向短程有序的出现和取向有序参数的临界涨落的影响。根据涉及定向短程有序簇的模型来分析结果。该模型中定义的单分子停留时间 tau R 簇寿命 tau 0 和簇浓度 C 被确定为温度的函数。在 Tc 处，获得以下值：tau R=0.6*10-11 s； tau 0 大约=2*10-10 s； C=0.4。
A study of the order-disorder phase transition of p-terphenyl (C18H14) by quasielastic incoherent neutron scattering is presented. Far from the transition point the measured quasielastic spectra reveal either the dynamics of an almost random disorder of molecular orientation (T>Tc) or a nearly static behaviour corresponding to orientational long-range order, but still including a small amount of dynamic disorder (T<Tc). In the neighbourhood of Tc, however, the quasielastic incoherent neutron spectra are clearly affected by the appearance of orientational short-range order and critical fluctuations of the orientational order parameter. The results are analysed in terms of a model involving orientationally short-range-ordered clusters. The single-molecule residence time tau R cluster lifetime tau 0 and cluster concentration C as defined in this model, are determined as a function of the temperature. At Tc the following values are obtained: tau R=0.6*10-11 s; tau 0 approximately=2*10-10 s; C=0.4.
α-(ET)2IBr2的有序-无序相变
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
Y. Yue;C. Nakano;K. Yamamoto;M. Uruichi;K. Yakushi;A. Kawamoto
通讯作者：
A. Kawamoto