PREPARATION AND CHARACTERIZATION OF Nd-Fe-B FILMS WITH HIGH COERCIVITY

高矫顽力Nd-Fe-B薄膜的制备及表征

基本信息

批准号：
12650310
负责人：
OKUDA Takashi
金额：
$ 0.32万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650310/
关键词：
Thin Film Permanent Magnet Nd_2Fe_<14>B Crystallization by Heat Treatment Substrate Temperature Perpendicular Magnetic Film Columnar Structure Single Domain Particle High Coercivity 単磁区粒子

项目摘要

In order to develop thin film permanent magnet (TFPM) necessary for miro- or nanb-devices, preparation and characterization of Nd-Fe-B films with very high coercivity have been investigated. As the high coercivity is the most important material requisite for TFPM, we concentrated to find target composition which may result high coercivity. We prepared the films by RF-sputtering with subsequent heat treatment. As-deposited films were in amorphous state and magnetically very soft with strong in-plane magnetic anisotropy. We found that some of the as-deposited films prepared under special conditions have very weak out-of-plane anisotropy. In those films heat treated under appropriate conditions, Nd_2Fe_<14>B phase crystallizes with c-axis oriented along the film normal. We named such a phenomenon as self-texturing crystal growth.As the c-axis is magnetic easy direction, the film is easily magnetized perpendicular to the film plane. The films show prominent permanent magnet characteristics: coercivity higher than 15kOe, residual flux density of 9kG, and maximum energy product (BH)_<max> as high as 20.1MGOe. Such a high coercivity may be resulted from Nd_2Fe_<14>B crystallites of which size is as large as single domain size and c-axis is orienting along film normal. We consider that such a fine crystallite size maybe in relation with nucleation density in self-texturing crystal growth.

为了开发薄膜的永久磁铁（TFPM），对米罗或nanb devices进行了必要的情况，已经研究了具有非常高的矫正性的ND-FE-B膜的制备和表征。由于高强度是TFPM所需的最重要的材料，因此我们集中于寻找可能导致高矫正率的目标组成。我们通过随后的热处理进行射频输出来制备膜。沉积的膜处于无定形状态，磁性非常柔软，平面内磁各向异性。我们发现，在特殊条件下制备的一些备受沉积的膜的面外各向异性非常弱。在那些在适当条件下进行热处理的膜中，ND_2FE_ <14> B相沿膜正常的C轴结晶。我们将这种现象命名为自质晶体生长。由于c轴是磁性的方向，因此膜很容易垂直于膜平面磁化。这些膜显示出明显的永久磁铁特性：高于15KOE的胁迫，9kg的残余通量密度和最大能量产物（BH）_ <max>高达20.1mgoe。这种高的矫正性可能是由ND_2FE_ <14> B晶体构成的，其大小与单个域大小和C轴一样大，而C轴则沿膜正常。我们认为，如此细的结晶石大小可能与晶体生长的成核密度有关。