Investigation of Alkaline metal vibration effect on the electric states in β-pyrochlore oxides

β-焦绿盐氧化物中的碱性原子以异常大的振幅振动。在-焦绿盐氧化物的超导态中，预期大振幅振动将起重要作用。本文成功地估计了具有大振幅振动异常特征的振动的非调和性，并揭示了KOs_2O_6中K的振动具有异常大的非调和性。通过一系列的非调和性研究，确定了影响非调和性的重要因素，揭示了实现大非调和性的原理。

Alkaline atoms in the β-pyrochlore oxides vibrate with unusually large amplitude. The large amplitude vibrations are expected to take an important role in the superconducting state of the -pyrochlore oxides. In this investigation, anharmonicity of the vibrations, which characterizes the anomaly of the large amplitude vibrations, is successfully estimated, and it is revealed that K vibrations in KOs_2O_6 possess anomalously large anharmonicity. From a series of anharmonicity investigations, an important factor to affect anharmonicity has been determined, and a principle to realize large anharmonicity has been revealed.