Crystal Orientation of Anisotropic Fe-Pt Permanent Magnet

各向异性铁铂永磁体的晶体取向

• 批准号: 11450265
• 负责人: WATANABE Masato
• 金额: $ 0.96万
• 依托单位: The Research Institute for Electric and Magnetic Materials(RIEMM)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450265/
• 关键词: Fe-Pt permanent magnet alloy; Ordered phase alloy; Single crvstal; Maximum energy product; Solution growth; Fe-Pt系合金; 永久磁石; 規則相合金; 精密鋳造法; 結晶方位

The head investigator in this project and his collaborates succeeded in fabricating c-axis oriented Fe-Pt based alloy thin films with the energy product exceeding 35 MG-Oe, which is the highest value as thin film magnets. Thus, apparent improvement of magnetic properties in bulk Fe-Pt alloys is expected by controlling their crystal orientation. In this project, we laid a research plan of investigating crystal orientation dependence of magnetic properties in Fe-Pt single crystals. This plan aims at adapting to shape multiplicity of permanent magnets and at optimizing magnetic properties of this alloy. Single crystal preparation of Fe-Pt alloy has been reported to be difficult, due to the formation of twin microstructures to release stress of order-disorder transformation. First, we prepared Fe-37at%Pt single crystals and investigated orientation dependence of magnetic properties in the sample aged at 640℃. In the case of the sample aged for 45 hours, showing the maximum coercivity, apparent difference of coercivity could not be observed between the directions of magnetization easy axis [001] and hard axis [100]. However, we could confirm a difference of coercivity by a factor of 2 in the over-aged sample (for 280 hours). On addition to the 37 at%Pt composition, fabrication of Fe- 39.5 at%Pt- 0.75 at%Nb single crystal was attempted by precise casting method using a molding material with low heat conductivity, resulted in a single crystal grain with the size of 2mm length. Solution growth of Fe-Pt single crystal was also attempted using Fe-Pt-B pseudo binary alloys as solvent.

该项目的首席研究员及其合作者成功地制备了c轴取向的Fe-Pt基合金薄膜，其能量积超过35 MG-Oe，这是薄膜磁体的最高值。因此，明显改善磁性能的块状Fe-Pt合金，预计通过控制其晶体取向。在本计画中，我们提出研究铁铂单晶磁性与晶向的关系。该计划旨在适应形状多样性的永磁体，并优化该合金的磁性能。Fe-Pt合金的单晶制备一直被报道是困难的，这是由于形成孪晶显微结构来释放有序-无序转变的应力。首先，我们制备了Fe-37at%Pt单晶，并研究了640℃时效样品的磁性能与取向的关系。在老化45小时的样品中，显示出最大磁化率，在易磁化轴[001]和难磁化轴[100]方向之间没有观察到明显的磁化率差异。然而，我们可以确认过度老化样品（280小时）中的结晶度差异为2倍。除了37at%Pt成分外，还尝试使用具有低导热性的成型材料通过精密铸造方法制备Fe-39.5at%Pt-0.75at%Nb单晶，得到尺寸为2 mm长的单晶颗粒。本文还尝试了以Fe-Pt-B准二元合金为溶剂的溶液法生长Fe-Pt单晶。

项目成果

M. Watanabe, T. Masumoto, D.H. Ping and K. Hono: "Microstructure and magnetic properties of FePt-Al-0 granular thin films"Applied Physics Letters. Vol. 76. 3971-3973 (2000)

M. Watanabe、T. Masumoto、D.H. Ping 和 K. Hono：“FePt-Al-0 颗粒薄膜的微观结构和磁性”应用物理快报。

Masato Watanabe, Tsuyoshi Masumoto: "Extraordinary Hall effect in Fe-Pt alloy thin films and fabrication of micro Hall devices"Thin Solid Films. 405巻1-2号. 92-97 (2002)

Masato Watanabe，Tsuyoshi Masumoto：“Fe-Pt 合金薄膜中的非凡霍尔效应和微型霍尔器件的制造”，《固体薄膜》第 405 卷，第 92-97 期（2002 年）。

M. Watanabe and T. Masumoto: "Extraordinary Hall effect in Fe-Pt alloy thin films and fabrication of micro Hall devices"Thin Solid Films. Vol. 405. 92-97 (2002)

M. Watanabe 和 T. Masumoto：“Fe-Pt 合金薄膜中的非凡霍尔效应和微型霍尔器件的制造”固体薄膜。

De-Hai Ping, Masato Ohnuma, Kazuhiro Hono, Masato Watanabe, Tadayoshi Iwasa, Tsuyoshi Masumoto: "Microstructures of FePt-Al-O and FePt-Ag nanogranular thin films and their magnetic properties"Journal of Applied Physics. 90巻9号. 4708-4716 (2001)

De-Hai Ping、Masato Ohnuma、Kazuhiro Hono、Masato Watanabe、Tadayoshi Iwasa、Tsuyoshi Masumoto：“FePt-Al-O 和 FePt-Ag 纳米颗粒薄膜的微观结构及其磁性”，应用物理学杂志，第 90 卷。 . 9. 4708-4716 (2001)

Masato Watanabe, Tsuyoshi Masumoto, De-Hai Ping, Kazuhiro Hono: "Microstructure and magnetic properties of FePt-Al-O granular thin films"Applied Physics Letters. 76巻26号. 3971-3973 (2000)

Masato Watanabe、Tsuyoshi Masumoto、De-Hai Ping、Kazuhiro Hono：“FePt-Al-O 颗粒薄膜的微观结构和磁性”应用物理快报第 76 卷，第 26 期。3971-3973 (2000)