Synthesisand properties of C_<60> based mutielement compounds

我们开展了富勒烯基固体的基础性研究，取得了以下成果。富勒烯聚合物我们通过对分子化合物(ET)2C60进行高压-高温处理，成功地选择性地合成了富勒烯二聚体，它是C60的2-2环加成物。通过差示扫描量热法对二聚体、一维聚合物和二维聚合物进行了比较，明确了富勒烯的所有聚合形式都比单体形式更稳定。在这项工作中建立了富勒烯聚合物的能量学。2.多元富勒烯超导体2-1：NH_3K_3C_2O超导体-绝缘体的反铁磁序转变是固体物理中普遍存在的基本问题之一。在富勒烯的情况下，这种转变是通过将NH_3分子插入到…中而发生的更多的超导K3C60。我们用各种手段研究了非超导NH_3K_3C_6O，以阐明超导体-非超导体转变的机制。我们发现NH_3K_3C_6O的电子基态是一个反铁磁性绝缘体。这一结果清楚地表明，NH_3K_3C_6O中超导电性的损失是由磁性引起的，这为众所周知的铜酸盐和有机超导体提供了一个很好的类比。2-2：(NH_3)_xNaA_2C_6O(0.5&lt；x&lt；L，A=K，Rb)超导体的高压效应标题超导体的T_c与晶格参数之间的反常关系与标准的A_3C_(60)超导体的结果相反。在静压下研究了T_c/L晶格参数的关联，表明这些氨化超导体的T_c不再简单地受富勒烯间距的影响。2-3：高掺杂态超导体。非价K3Ba3C6O和低价K2Ba4C6O表明，高掺杂态的超导电性判据与低掺杂态的超导电性判据明显不同。较少

We have carried out a fundamental research on fullerene based solids and obtained the following results.1. Fullerene polymersWe have succeeded to selectively synthesize a fullerene dimer, which is a 2+2 cycloadduct of C60, by a high pressure-high temperature treatment of a molecular compound(ET)2C60. Comparing the dimer, one-dimensional polymer, and two-dimensional polymers by means of differential scanning calorimetry measurements, we clarified that all the polymeric forms of fullerenes are more stable than the monomer form. The energetics of the fullerene polymers are established in this work. The energy difference between these polymeric phases are smaller than the difference between graphite and diamond.2.Multinary fullerene superconductors2-1 : Antiferromagnetic order in NH3K3C6OSuperconductor-insulator transition is one of the universal and fundamental problems in solid state physics.In the case of fullerenes, this transition takes place by an intercalation of NH3 molecules into … More superconducting K3C60. We have investigated the nonsuperconducting NH3K3C6O by various means to clarify the mechanism of superconductor-nonsuperconductor transition. We found that the electronic ground state of NH3K3C6O is an antiferromagnetic insulator. This result clearly shows that he loss of superconductivity in NH3K3C6O is of magnetic origin, providing a nice analogy to the well know cuprate and organic superconductors.2-2 : High pressure effect of (NH3)xNaA2C6O(O.5<x<l, A=K, Rb)superconductorsThe title superconductors shows an anomalous correlation between Tc and lattice parameter, which is opposite to the one found in the standard A3C60 superconductors. The Tc/llattice parameter correlation was investigated under hydrostatic pressure, showing that Tc of these ammoniated superconductors is not scaled any more simply by the interfullerene spacings.2-3 : Superconductor at highly doped statesNew fullerene superconductors with highly doped states are found. The nonavalent K3Ba3C6O and decavalent K2Ba4C6Oshowed that the criterion of superconductivity in the highly doped state is significantly different form that of the low doped systems. Less