STUDY FOR MECHANISM OF GIANT EXCHANGE ANISOTROPY AND DEVELOPMENT OF HIGH PERFORMANCE Mn BASED ANTIFERROMAGNETIC MATERIALS

巨交换各向异性机理研究及高性能锰基反铁磁材料的开发

• 批准号: 18360144
• 负责人: TSUNODA Masakiyo
• 金额: $ 10.27万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18360144/
• 关键词: Exchange anisotorpy; Spinelectronics; hard disk drive; MRAM; Magnetic anisotropy; XMCD; Antiferromagnetism

The exchange anisotropy is a phenomenon to fix the spins in ferromagnet and utilized in spintronics devices such as magnetic random access memories and spin valve type reproducing head element in ultrahigh density magnetic recording system. The purpose of the present study is to understand the mechanism of exchange anisotropy and to develop the high performance antiferromagnetic materials, through the study of inducing mechanism of giant exchange anisotropy (J_K=1.3 erg/cm^2) that has been discovered by the present authors group. In this research project, following terms have been investigated. 1. Correlation between the microstructure and exchange anisotropy of the exchange biased bilayers. 2. Spin structure and magnetization process of antiferromagnetic layer by soft x-ray magnetic circular dichroism (XMCD). 3. Development of microscopic model for exchange biased bilayers and theoretical calculations. 4. Fabrication and estimation of theoretically designed practical exchange biased bilayers. Main results obtained are summarized as follows. Uncompensated antiferromagnetic spin induced at the interface was quantitatively investigated by XMCD technique. The uncompensated antiferromagnetic spins change their sign and magnitude, as the ferromagnetic Co-Fe layer composition is changed. While, the exchange biasing strength is also changed as a function of the Co-Fe composition, close correlation has been suggested between them. Standing on the above finding, ultra-thin Mn layer insertion at the interface has been designed to enhance the exchange anisotropy and experimentally confirmed the doubling strength of exchange anisotropy. From a dependence of exchange anisotropy on the antiferromagetic layer composition, it is suggested that the inserted Mn layer has 3Q spin structure differently from the bulk Mn, in order to trace the fcc structure of the underlying Mn-Ir layer.

交换各向异性是一种将自旋固定在铁磁体中的现象，被用于超高密度磁记录系统中的自旋电子学器件，如磁随机存取存储器和自旋阀型再现磁头元件。本研究的目的是通过对本课题组发现的巨型交换各向异性(J_K=1.3erg/cm~2)的诱导机制的研究，了解交换各向异性的形成机理，开发高性能的反铁磁材料。在本研究项目中，对以下术语进行了调查。1.交换偏置双层膜的微结构与交换各向异性之间的关系2.软X射线磁性圆二色谱(XMCD)反铁磁层的自旋结构和磁化过程3.交换偏置双层膜微观模型的建立和理论计算。4.理论设计的实用交换偏置双层膜的制备和估算。取得的主要成果概括如下。用XMCD技术定量研究了界面诱导的未补偿反铁磁自旋。随着铁磁性Co-Fe层成分的改变，未补偿的反铁磁自旋的符号和大小也随之改变。同时，交换偏置强度也随着Co-Fe组分的变化而变化，二者之间存在着密切的相关性。基于上述发现，设计了在界面处插入超薄Mn层来增强交换各向异性，并从实验上证实了交换各向异性的倍增强度。根据交换各向异性对反铁磁层成分的依赖关系，提出插入的Mn层具有与体相不同的3q自旋结构，以跟踪下面的Mn-Ir层的面心立方结构。

项目成果

Enhancement of exchange bias by ultra‐thin Mn layer insertion at the interface of Mn‐Ir/Co‐Fe bilayers

• DOI: 10.1002/pssb.200777391
• 发表时间: 2007-12
• 期刊: physica status solidi (b)
• 作者: M. Tsunoda;S. Yoshitaki;Y. Ashizawa;Dong Young Kim;C. Mitsumata;M. Takahashi

XMCD study of Mn-Ir/Co-Fe bilayers with giant exchange anisotropy

具有巨大交换各向异性的Mn-Ir/Co-Fe双层的XMCD研究

• 发表时间: 2006
• 作者: Y. Iida;T. Mori;M. Tsunoda;D. Y. Kim;K. Komagaki;M. Tsunoda;D. Y. Kim;角田匡清;K. Komagaki;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M.Tsunoda;D.Y.Kim;M.Tsunoda;M.Tsunoda;M.Tsunoda;D.Y.Kim;M. Tsunoda;M. Tsunoda;M. Tsunoda;角田匡清;角田匡清;三俣千春;M. Tsunoda;M. Tsunoda;C. Mitsumata;M. Takahashi;M. Takahashi;M. Takahashi;D. Y. Kim;D. Y. Kim;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tsunoda;M. Tsunoda;M. Tsunoda;M. Tsunoda;D.Y. Kim;D. Y. Kim;M. Tsunoda;M. Tsunoda;K. Komagaki;K. Komagaki;D.Y. Kim;角田匡清;角田匡清;中村哲也;D. Y. Kim;M. Tsunoda;M. Tsunoda;T. Nakamura;駒垣幸次郎;K. Komagaki;M. Tsunoda
• 通讯作者: M. Tsunoda

交換バイアス反強磁性材料

交换偏压反铁磁材料

• 发表时间: 2007
• 期刊: 金属 77
• 作者: Y. Iida;T. Mori;M. Tsunoda;D. Y. Kim;K. Komagaki;M. Tsunoda;D. Y. Kim;角田匡清
• 通讯作者: 角田匡清

Enhancement of exchange anisotropy by ultra-thin Mn layer insertion at the interface of Mn-Ir/Co-Fe bilayers

通过在 Mn-Ir/Co-Fe 双层界面插入超薄 Mn 层增强交换各向异性

• 发表时间: 2007
• 作者: Y. Iida;T. Mori;M. Tsunoda;D. Y. Kim;K. Komagaki;M. Tsunoda;D. Y. Kim;角田匡清;K. Komagaki;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M.Tsunoda;D.Y.Kim;M.Tsunoda;M.Tsunoda;M.Tsunoda;D.Y.Kim;M. Tsunoda;M. Tsunoda;M. Tsunoda;角田匡清;角田匡清;三俣千春;M. Tsunoda;M. Tsunoda
• 通讯作者: M. Tsunoda

交換結合バイアス積層膜における反強磁性層臨界膜厚の低減

交换耦合偏置堆叠薄膜中临界反铁磁层厚度的减小

• 发表时间: 2007
• 作者: Y. Iida;T. Mori;M. Tsunoda;D. Y. Kim;K. Komagaki;M. Tsunoda;D. Y. Kim;角田匡清;K. Komagaki;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M. Tsunoda;M. Tsunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M. Tsunoda;D. Y. Kim;M.Tsunoda;D.Y.Kim;M.Tsunoda;M.Tsunoda;M.Tsunoda;D.Y.Kim;M. Tsunoda;M. Tsunoda;M. Tsunoda;角田匡清;角田匡清;三俣千春
• 通讯作者: 三俣千春