A Study on the Formation Process of Long Period Superlattice Structures in Alloys

合金中长周期超晶格结构形成过程的研究

• 批准号: 62540224
• 负责人: FUJINO Yutaka
• 金额: $ 1.22万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62540224/
• 关键词: antiphase boundary structure in Ag-Mg alloys; order-disorder transition; incommensurate-commensurate transition; charge density wave; フェルミ面のネスティング; 電荷密度波; ポテンシャル・エネルギー波; 合金の逆位相長周期構造の安定性; 銀-マグネシウム合金の逆位相長周期構造; ポテンシャル; エネルギー波; ポテンシャルエネルギー波

Structural order-disorder transition in metalic alloys have been investigated extensively for more than 60 years from both theoretical and experimental points of view. A number of pioneering experimental works have been performed by the x -ray, the neutron and the electron diffraction measurements. However, order-disorder transitions do not necessarily proceed homogeneously in every portion of the specimen, but it is usually heterogeneous phenomena and develops by the mechanism of nucleation and growth. Thus, it becomes important to do observation not only in reciprocal space but also in real space microscopically.In the present work, formation process of long period superlattice from disordered phase in Ag-Mg alloys has been studied by means of transmission electron microscopy. It was found for the first time that the ordering was preceded by a metastable state in which ordered and disordered (or weakly ordered) regions were periodically arranged spatially. The nesting of the fermi surface is proposed as the origin of this type of ordering.

60多年来，人们从理论和实验两方面对金属合金的有序-无序转变进行了广泛的研究。通过x射线、中子和电子衍射测量进行了许多开创性的实验工作。然而，有序-无序转变不一定在试样的每个部分都均匀进行，但它通常是异质现象，并通过成核和生长机制发展。因此，不仅要在互反空间中进行微观观察，而且要在实空间中进行微观观察。本文用透射电镜研究了银镁合金中无序相长周期超晶格的形成过程。首次发现，在有序之前存在一个亚稳态，其中有序和无序（或弱有序）区域在空间上周期性排列。费米曲面的嵌套被认为是这种排序的起源。

项目成果

Y.FUJINO;H.SATO;M.HIRABAYASHI;E.AOYAGI;Y.KOYAMA: Physical Review Letters. 58. 1012-1015 (1987)

Y.FUJINO；H.SATO；M.HIRABAYASHI；E.AOYAGI；Y.KOYAMA：物理评论快报。

藤野豐: 物性研究. 50. 306-314 (1988)

藤野文：凝聚态材料研究。50。306-314（1988）

H,SATO;Y.FUJINO;M,HIRABAYASHI;Y.KOYAMA: Proc.Int.Symp.Dynamics of Ordering Process in Condensed Matter,Kyoto (1987). 519-524 (1988)

H，佐藤；Y.藤野；M，平林；Y.小山：Proc.Int.Symp.凝聚态物质有序过程动力学，京都（1987）。

Y.FUJINO: Physical Review Letters.

Y.FUJINO：物理评论快报。

Y. Fujino; H. Sato; M. Hirabayashi: "In Situ Observation of Commensuration Process of Long Period Superlattice in the Ag-Mg alloys." Proc. Int. Conf. Phase Transformations '87.585-587 (1988)

Y.藤野；