High resolution photoelectron spectroscopy of organic conducting materials

为了弄清有机材料在超导和非超导相变温度附近的电子结构变化，对超高分辨率光电子能谱仪的样品保持系统进行了改进。改进后的样品架杆体温度降至10K以下，但样品盘本身的温度不足以研究样品的相变。另一项修改正在进行中。在修饰的同时，还测量了金属富勒烯和直链碳链分子的光电子能谱。金属富勒烯由富勒烯笼子和金属原子组成，金属原子给笼子提供电子。金属富勒烯的电子结构随着转移电子的数量和自旋态的不同而发生很大的变化。我们已经阐明了三个Tm@C82异构体和一个Pr@C82次异构体的电子结构。我们发现Tm@C82中有两个电子转移到笼子中，而Pr@C82中有三个电子转移到笼子中。线型碳链分子被认为是分子线的潜在候选者之一。我们发现，链越长，最高占据的分子轨道越不稳定，这些分子可以作为一维量子阱的一个很好的例子。

In order to clarify the electronic structure change around the superconductive and non superconductive phase transition temperature of organic materials, a sample holding system of a ultrahigh resolution photoelectron spectrometer was modified. After the modification, temperature of the sample holder stem went down to less than 10 K which was the aim of modification, but the sample disk itself was not cold enough to investigate the phase transition. Another modification is under the way. Parallel to the modification, photoelectron spectra of metallofullerenes and linear carbon chain molecules have been measured. Metallofullerenes consist of fullerene cages and metal atoms and metal atoms donate electron the cage. Electronic structures of metallofullerenes change drastically according to the amounts of transferred electrons and their spin states. We have clarified the electronic structures of three Tm@C82 isomers and a Pr@C82 minor isomer. We found that two electrons are transferred to the cage in Tm@C82, whereas three electrons are transferred in Pr@C82. Linear carbon chain molecules are considered to be one of prospective candidates for molecular wire. We found that the longer the chain, the less stable the highest occupied molecular orbit and these molecules can be treated as a good example of one-dimensional quantum well.