## 抄録

The bandshape of the intervalence absorption of SbC1_{6} ^{3-} and SbCl_{6} ^{-}, has been measured from 300 to 4 K in a crystal of (CH_{3}NH_{3}) _{2}Sb_{x}Sn_{1-x}, C1_{6} in order to study the variation of the zeroth, first and second moments. At all temperatures the bandshape is Gaussian, as required by the vibronic model of Piepho, Krausz and Schatz (P.K.S.) in the weak-interaction limit. From the temperature dependence of the second moment, we estimate the electronphonon coupling constant (and hence the displacement in vibrational coordinate from the ground state to the intervalence charge-transfer state), together with the effective phonon frequency coupled to the transition. The latter is very close to the mean of the ground-state totally symmetric Sb-Cl strtching modes of SbCl_{6} ^{3-} and SbCl_{6} ^{-} and the displacement in vibrational coordinate is also about half the difference between the Sb-Cl crystallographic bond lengths in the two complex ions. To explain the temperature dependence of the zeroth and first moments anharmonicity must be involved. A simple model for the variation of intervalence excitation energy with interionic distance, combined with an isotropic model of the thermal lattice expansion, gives a quantitative account of the change in first moment with temperature and a qualitative description of the change in zeroth moment.

本文言語 | English |
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ホスト出版物のタイトル | Molecules into Materials |

ホスト出版物のサブタイトル | Case Studies in Materials Chemistry-Mixed Valency, Magnetism and Super Conductivity |

出版社 | World Scientific Publishing Co. |

ページ | 389-399 |

ページ数 | 11 |

ISBN（電子版） | 9789812706836 |

ISBN（印刷版） | 9812700382, 9789812700384 |

DOI | |

出版ステータス | Published - 2007 1月 1 |

## ASJC Scopus subject areas

- 化学 (全般)
- 工学（全般）
- 材料科学（全般）
- 物理学および天文学（全般）