Structure of Lattice-Matched Fluoride Films

晶格匹配氟化物薄膜的结构

• 批准号: 60460231
• 负责人: HASHIZUME Hiroo
• 金额: $ 3.97万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60460231/
• 关键词: Mixed Fluoride; Thin Film; X-Ray Diffraction; Standing Wave; 構造解析; 格子準整合形弗化物混晶; エピタキシー結晶の界面原子構造; 表面X線定在波法; 微小入射角X線回折

The atomic structure of a single-crystal Ca_xSr_<1-x>F_2 (x = 0.43) film grown on GaAs(111)B surface has been determined with the X-ray standing-wave technique. A new method has been applied which allows complete analysis of mismatched structures using a single specimen. (Ca, Sr) atoms at the interface are found seven-coordinated, supporting the previously proposed growth model of epitaxial cubic fluoride films. The atomic layer spacing across the interface is contracted by 0.37 <Ang> compared with that calculated from the bulk bond lengths. The film is strained in such a way that the (111) interplanar distance is contracted by 0.28 %, although bulk mixed fluoride exactly lattice matches GaAs at room temperature, The study is based on a theoretical re-investigation of the standing-wave position with respect to atomic planes in absorbing non-centrosymmetric crystals.

采用X射线驻波技术测定了GaAs(111)B表面生长的单晶Ca_xSr_<1-x>F_2(x=0.43)薄膜的原子结构。应用了一种新方法，可以使用单个样本对不匹配的结构进行完整分析。界面处的（Ca，Sr）原子是七配位的，支持了先前提出的外延立方氟化物薄膜的生长模型。与根据体键长计算的结果相比，界面上的原子层间距收缩了 0.37 <Ang>。尽管块状混合氟化物在室温下与 GaAs 的晶格完全匹配，但薄膜的应变使得 (111) 面间距离收缩了 0.28%。该研究基于对驻波位置的理论重新研究相对于吸收非中心对称晶体中的原子平面。

项目成果

Y. Saitoh: Japanese Journal of Applied Physid. 27. (1988)

Y. Saitoh：日本应用物理学杂志。

O.Sakata: Report RLEMTIT. 12. (1987)

O.Sakata：报告 RLEMTIT。

H.Hashizume: Acta crystallographica. A43. (1987)

H.Hashizume：晶体学报。

Yoshiharu Saitoh, Hiroo Hashizume and Kazuo Tsutsui: "Structure Analysis of Lattice-Matched Ca_xSr_<1-x>F_2 Epilayers by the X-Ray Standing- Wave Method" Japanese Journal of Applied Physics. 27. (1988)

Yoshiharu Saitoh、Hiroo Hashizume 和 Kazuo Tsutsui：“通过 X 射线驻波法对晶格匹配 Ca_xSr_<1-x>F_2 外延层进行结构分析”《日本应用物理学杂志》。

O.Sakata: Acta crystallographica. A43. (1987)

O.Sakata：晶体学报。