Fabrication of Hard magnetic Amorphous Films Prepared by Laser Ablation Method and their properties

激光烧蚀法制备硬磁非晶薄膜及其性能

基本信息

批准号：
09650753
负责人：
TAKEUCHI Akira
金额：
$ 1.98万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (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-09650753/
关键词：
Laser Ablation Amorphous Thin Film Hard Magnetism Nano Crystallization Soft Magnetism Droplet Particle 非晶質薄膜

项目摘要

Nd-Fe base thin films with a thickness of up to 50 mum were prepared by laser ablation method. The surface of the thin films consists of a smooth layer and droplet particles abnormally grown. The droplet particles were characteristics of the Nd-based thin films and were not observed on the surface of the Fe-based thin films. The X-ray diffraction patterns exhibits broad halo with sharp peaks, indicating the coexisting of amorphous phase and alpha-Nd crystals. The sharp peaks disappeared when the droplet particles were removed. The saturation magnetization and coercive force of the Nd-based thin film with a thickness of 25 mum are 0.11 T and 13.5 kA/m, respectively. The coercive force is higher than that of the ribbon specimens prepared by melt-spinning. These thin films shows soft magnetism with a maximum coercive force of 2 kA/m. On the other hand, thin films prepared under an annealed state exhibit hard magnetism for both Nd-Fe binary and Nd-rich Nd-Fe-B ternary thin films which consisting of amorphous and crystalline phase while the other Nd-Fe base thin films exhibit amorphous single phase. Nd-richNd-Fe-B thin film prepared at 873 K increases in coercive force, and the magnetization does not saturate in an applied field of 1.256 MAIm. This phenomenon differs from that for button shaped specimens prepared by arc melting method : The coercive force of the button shpaped specimen is 300 kA/m and increase in coercive force when they were annealed. The thin films show soft magnetism due to rapid quenching which restrict structural relaxation in the specimens. It is clarified that thin films prepared by laser ablation method do not exhibit hard magnetism in an amorphous single state while hard magnetism was observed with a mixture of amorphous and nanocrystalline phase.

通过激光消融方法制备厚度高达50摄氏度的ND-FE碱基薄膜。薄膜的表面由光滑的层和液滴颗粒异常生长。液滴颗粒是基于ND的薄膜的特征，在Fe基薄膜的表面没有观察到。 X射线衍射模式表现出宽阔的光环，并表明无定形相和α-ND晶体共存。去除液滴颗粒时，锋利的峰消失了。厚度为25 MUM的ND基薄膜的饱和磁化和强制性分别为0.11 t和13.5 ka/m。强制力高于通过熔体旋转制备的带状标本的强制性。这些薄膜显示出柔软的磁性，最大强制力为2 ka/m。另一方面，在退火状态下制备的薄膜对ND-FE二进制和ND富含ND-FE-F-B Ternary薄膜都表现出硬磁性，该薄膜由无定形和结晶阶段组成，而其他ND-FE碱基薄膜则展示无定形的单相。在873 K中制备的ND-Richnd-Fe-B薄膜在强制力中增加，并且在1.256 Maim的应用场中磁化不饱和。这种现象与通过弧形熔化方法制备的按钮形样品的不同之处：纽扣SHPAPED样品的强制力为300 ka/m，在退火时会增加强制性。薄膜由于快速淬火而显示出柔软的磁性，这限制了标本中的结构松弛。可以澄清的是，通过激光消融方法制备的薄膜不会在无定形的单个状态下表现出硬磁性，而用无定形和纳米晶相的混合物观察到硬磁性。