Experimental study on the response of phason strains of the quasicrystals

准晶相子应变响应的实验研究

• 批准号: 09650758
• 负责人: MATSUO Susumu
• 金额: $ 2.11万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650758/
• 关键词: quasicrystal; icosahedral phase; phason; strain; strain relaxation; magnetic susceptibility

The dependence of the magnetic susceptibility on time was investigated in F-type Al-Pd-Mn icosahedral alloys after the change in the temperature. The susceptibility varied as a square root of time, which is characteristic of the relaxation of the phason in the theory of the strain response of the quasicrystal. Such a change in the susceptibility was considered to originate from the critical conditions for the formation of local magnetic moments in the Al-Pd-Mn icosahedral alloys, which resulted in the fact that only a small fraction of the whole Mn atoms had magnetic moment. These facts leaded to the investigations of the atomic positions in the Al-Pd-Mn icosahedral phases and related crystal approximants. Atomic clusters and the positions of Mn atoms were determined in the investigations, and a new structure related to the phason strains was found. The study of the time-dependence of the macroscopic strain is under way on applying stress.Simulation calculations were performed for the magnetic structures in a model of atomic positions of Ho in F-type Zn-Mg-Ho icosahedral phase at low temperatures on the assumption that the Ho atoms were interacting via RKKY-like alternating interactions. A long-range antiferromagnetic order was found in the case of the antiferromagnetic interaction for the shortest Ho-Ho distance and the ferromagnetic one for the second shortest Ho-Ho distance. Only a short-range antiferromagnetic order was found in the case of the reversed sign interactions. These facts strongly suggest that the phason strains affect the magnetism of the icosahedral phases drastically.

研究了F型Al-Pd-Mn二十面体合金在温度变化后磁化率随时间的变化规律。磁化率随时间的平方根变化，这是准晶应变响应理论中相位松弛的特征。磁化率的这种变化被认为源于Al-Pd-Mn二十面体合金中形成局部磁矩的临界条件，这导致只有一小部分完整的Mn原子具有磁矩。这些事实导致了对Al-Pd-Mn二十面体相和相关晶体近似物中原子位置的研究。在研究中确定了原子团簇和Mn原子的位置，并发现了与相子应变有关的新结构。宏观应变随施加应力的时间依赖性的研究正在进行中。在假设Ho原子通过类RKKY交替相互作用的假设下，对低温下F型Zn-Mg-Ho二十面体相中Ho原子位置模型中的磁结构进行了模拟计算。在HO-HO距离最短的反铁磁相互作用和第二短的HO-HO距离的铁磁相互作用的情况下，发现了长程反铁磁有序。在反号相互作用的情况下，只发现了短程反铁磁序。这些事实强烈地表明，相子应变对二十面体相的磁性有很大的影响。

项目成果

M.de Boissieu: "Reversible transformation between an icosahedral Al-Pd-Mn phase and a modulated structure of cubic symmetry" Phil.Mag.A. 78・2. 305-326 (1998)

M. de Boissieu：“二十面体 Al-Pd-Mn 相与立方对称调制结构之间的可逆转变”Phil.Mag.A. 78・2 (1998)。

S.Matsuo: "Magnetic susceptibility change in the Al-Pd-Mn icosahedral quasicrystals obeying time dependence of phason relaxation" Solid State Commun.102・8. 575-578 (1997)

S.Matsuo：“遵循相子弛豫时间依赖性的 Al-Pd-Mn 二十面体准晶的磁化率变化”Solid State Commun.102・8 (1997)。

M.Mori: "Diffuse scattering and Huang Scattering in Ai-based icosahedral quasicrystals" Proc.of the Third Pacific Rim International Conference on Advanced Materials and Processing. 1455-1460 (1998)

M.Mori：“Ai 基二十面体准晶体中的漫散射和黄散射”，第三届环太平洋先进材料与加工国际会议论文集。

M.Mori: "Diffuse scattering of Al-Pd-Mn and Al-Cu-Fe icosahedral phase" Proc.6th Int.Conf.on Quasicrystals. (印刷中). (1997)

M.Mori：“Al-Pd-Mn 和 Al-Cu-Fe 二十面体相的漫散射”Proc.6th Int.Conf.on Quasicrystals（准晶体）（1997 年出版）。

S.Matsuo: "Anomalously slow change in magnetic susceptibility in the A170Pd21.5Mn8.5 icosahedral quasicrystals obeying time dependence of phason relaxation" Proc.6th Int.Conf.on Quasicrystals. 467-470 (1997)

S.Matsuo：“A170Pd21.5Mn8.5 二十面体准晶体中磁化率的异常缓慢变化，服从相子弛豫的时间依赖性”Proc.6th Int.Conf.on Quasicrystals。