Effect of Substitutional Impurities on the Neutral-to-Ionic Phase Transition in TTF- p -Chloranil Crystal
Effect of Substitutional Impurities on the Neutral-to-Ionic Phase Transition in TTF- p -Chloranil Crystal
复制标题
取代杂质对 TTF-对四氯苯醌晶体中性相变离子相变的影响
DOI：
10.1143/jpsj.53.4445
复制
发表时间：
1984
影响因子：
1.7
通讯作者：
T. Mitani
中科院分区：
文献类型：
--
作者：
Y. Tokura;T. Koda;G. Saito;T. Mitani
为了研究掺杂对中性-离子相变的影响，在不同温度和掺杂浓度下，测量了掺杂取代弱受主三氯对苯醌的TTF-对氯苯醌单晶的分子内激发反射光谱。与纯晶体在Tc =84 K处的光谱变化相比，掺杂使光谱的热位移变得相当模糊。它的结论是，在掺杂晶体中的相变发生不均匀，由于二元相分离成准离子和准中性区域，甚至低于Tc。在此基础上，提出了杂质对TTF-四氯苯醌晶体中性-离子相变影响的微观模型。
In order to investigate the effect of doping on the neutral-to-ionic phase transition, reflection spectra due to the intramolecular excitations have been measured on TTF- p -chloranil single crystals doped with the substitutional weak acceptor, trichloro- p -benzoquinone, at various temperatures and dopant concentrations. The thermal shifts of the spectra are considerably blurred by doping in contrast with a sharp spectral change at T c =84 K in pure crystal. It is concluded that the phase transition in doped crystals occurs inhomogeneously due to a binary phase separation into quasi-ionic and quasi-neutral regions even below T c . On the basis of these results, a microscopic model is presented for the effect of impurities on the neutral-to-ionic phase transition in TTF-chloranil crystal.