Understanding modulated Phases in Heusler Alloys

了解霍斯勒合金中的调制相

• 批准号: 159745067
• 负责人: Privatdozent Dr. Sebastian Fähler
• 金额: --
• 依托单位: Institut für Ionenstrahlphysik und Materialforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/159745067?language=en
• 关键词: Understanding; modulated; Phases; Heusler; Alloys

Modulated phases seem to be a general feature of various functional materials. In particular for Ni-Mn-Ga Heusler alloys, the 14M modulated martensite reaches the highest strain close to 10% in external magnetic fields. Recently we showed that this phase can be built from nanotwinned variants of the non-modulated (NM) martensite phase following the concept of adaptive martensite. In combination with branching this concept suggests microscopic explanations of the key features of this phase.Here we aim to understand the origin of the differently modulated phases observed in Heusler alloys in relation to composition, temperature, stress and magnetic fields. Structure and phase transformation of Ni-Mn-Ga and other Heusler alloys are examined in form of epitaxial films and bulk single crystals. Since modulated structures affect the material from the atomistic to the macroscopic length scale, dedicated integral diffraction methods in combination with high resolution local probes are applied. Finally consequences of the modulation for the functional properties of Heusler alloys are analyzed.

调制相似乎是各种功能材料的一般特征。特别是对于Ni-Mn-Ga Heusler合金，14 M调制马氏体在外磁场中达到接近10%的最高应变。最近，我们表明，这个阶段可以建立从非调制（NM）马氏体相的自适应马氏体的概念纳米孪晶变体。结合分支这一概念建议微观解释的关键特征，这一阶段。在这里，我们的目标是了解不同的调制相的Heusler合金中观察到的成分，温度，应力和磁场的起源。本文研究了Ni-Mn-Ga及其它Heusler合金的外延薄膜和单晶体的结构和相变。由于调制结构影响的材料从原子到宏观的长度尺度，专用的积分衍射方法结合高分辨率的本地探头应用。最后分析了调制对Heusler合金功能性能的影响。

项目成果

Localizing sources of acoustic emission during the martensitic transformation

马氏体转变过程中声发射源的定位

• DOI: 10.1103/physrevb.89.214118
• 发表时间: 2014
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: R. Niemann;J. Kopecek;O. Heczko;J. Romberg;L. Schultz;S. Fähler;E. Vives;L. Manosa;A. Planes
• 通讯作者: A. Planes