Coupling of Micromagnetic and Structural Properties Across the Martensite and Curie Temperatures in Miniaturized Ni‐Mn‐Ga Ferromagnetic Shape Memory Alloys
Coupling of Micromagnetic and Structural Properties Across the Martensite and Curie Temperatures in Miniaturized Ni‐Mn‐Ga Ferromagnetic Shape Memory Alloys
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DOI：
10.1002/adfm.201300165
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发表时间：
2013-10
影响因子：
19
通讯作者：
A. Jakob;M. Hennes;M. Müller;D. Spemann;S. G. Mayr
中科院分区：
文献类型：
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作者：
A. Jakob;M. Hennes;M. Müller;D. Spemann;S. G. Mayr
利用变温磁力显微镜（TD-MFM）研究了Ni-Mn-Ga铁磁形状记忆薄膜的微磁结构演化。感兴趣的中心是MgO衬底上的外延Ni-Mn-Ga薄膜在热致相变过程中的磁性。实验结果进行了讨论的框架内产生的应力薄铁磁薄膜的竞争磁相互作用。对14 M马氏体试样的测量通过三维微磁模拟进行补充。相应的计算MFM显微照片进行了比较，实验数据。从理论上描述了孪晶尺寸和取向对微磁畴形成和壁结构的影响。提出了部分磁通闭合的微磁模型系统，并通过解析计算来估计奥氏体Ni-Mn-Ga中的应力诱导磁晶各向异性常数。
Micromagnetic structure evolution in Ni‐Mn‐Ga ferromagnetic shape memory thin films is investigated by means of temperature dependent magnetic force microscopy (TD‐MFM). The center of interest is the magnetic properties of epitaxial Ni‐Mn‐Ga thin films on MgO substrates across thermally induced phase transitions. Experimental results are discussed within the framework of competing magnetic interactions arising in stressed thin ferromagnetic films. Measurements on 14M martensite specimens are supplemented by three‐dimensional micromagnetic simulations. Corresponding calculated MFM micrographs are compared to experimental data. The influence of twin variant dimension and orientation on micromagnetic domain formation and wall structure is depicted from a theoretical point of view. A micromagnetic model system of partial flux closure is proposed and calculated analytically to estimate a stress induced magneto crystalline anisotropy constant in austenite Ni‐Mn‐Ga.