Japan-CIS joint project for optical studies of new materials

在该研究项目中，我们邀请了4名俄罗斯科学家和1名乌兹别克斯坦科学家，并派遣了4名日本科学家前往俄罗斯、拉托维亚和爱沙尼亚，一名由JSPS资助的乌兹别克斯坦青年科学家也参加了该研究项目。通过此次交流项目，我们重点开展了固体富勒烯及其相关化合物的研究，其中一项成果是发现了一种新的超导三元化合物Na-N-C_<60>，这是第一个含Na的超导体。通过对合成方法的改进，利用X射线衍射、超导量子干涉仪、电子自旋共振和低场微波吸收等手段对样品的结构和超导性能进行了表征。我们认为，超导电性是由保护结晶相分离的氮物种引起的。在此基础上，我们扩展了含C_3的三元化合物<60>，第一种是通过碱金属掺杂有机分子间的电荷转移化合物， ...更多信息 在<60>略高于室温的中等温度下，发现掺杂的材料具有超导电性。碱金属掺杂聚烯烃噻吩C_2<60>体系显示出多相超导电性，<60><60><48><70><58>在IMS的UVSOR电子储存环的真空紫外激发（3A 1波荡器）下，进行了C_2，C_ F_2和C_ F_3的发光实验，在相变温度处发光强度出现明显的跳跃，说明虽然激发态是Frenkel型，但晶场的影响很强。另一方面，C_<60>F_2<48>和C_<70>F_3<58>的发光表现出一个复杂的弛豫过程，结合准分子激光激发的实验，得出其发光衰减曲线由三个分量组成的结论。最有趣的是，发光强度随着波荡器辐射的照射而降低。结果表明，这种现象与光解离过程有关，如CF的裂解。更详细的分析正在进行中。少

During this research project, we invited 4 Russian scientists and 1 Uzbekistan scientist and send 4 Japanese scientists to Russia, Latovia, and Estonia.A Uzbekistan young scientist sponsored by JSPS also joined this research project. Through this exchange program, we focused on the research on solid fullerenes and related compounds.One of our achievement is the discovery of a new superconducting ternary compound, Na-N-C_<60>, which is the first Na-containing superconductor. After the effort to improve the synthetic method, the structure and superconducting properties were characterized by X-ray diffraction, SQUID magnetometer, ESR,and low-filed microwave absorption. We proposed that the superconductivity was brought about by the nitrogen species which protects the disproportionation phase separation. Based on this successful result, we expanded the ternary compound involving C_<60>.The first one was prepared by the alkali-metal doping of the charge-transfer compound between organic-don … More or and C_<60>.We found a superconductivity in the materials doped at a moderate temperature slightly higher than room temperature. The doping of alkali-metal to the poly-alkey-thiophene C_<60> system showed a multi-phase superconductivity.The luminescence experiments of C_<60>, C_<60>F_<48> and C_<70>F_<58> was carried out under VUV excitation (undulator of beam line 3A1) from the UVSOR electron storage rings of IMS.The luminescence intensity showed a clear jump at the phase transition temperature which means that the effect of crystal field is very strong although the excited state is a Frenkel type. On the other hand the luminescence of C_<60>F_<48> and C_<70>F_<58> showed a complicated relaxation process.Combined with the experiment of the excimer laser excitation, it was concluded that the luminescence consists of three components in the decay curve. Most interestingly, the luminescence intensity decreased with the irradiation of the undulator radiation . It was evidenced that this phenomenon is related to the photo-dissociation process such as the cleavage of CF.More detailed analysis of the relaxation process is in progress. Less