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

• 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

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.

为了开发微纳器件所需的薄膜永磁体，研究了具有很高矫直力的NdFeB薄膜的制备和表征。由于高矫顽力是TFPM最重要的材料，我们集中精力寻找可能导致高矫顽力的靶材成分。我们采用射频溅射法制备了薄膜，并进行了后续的热处理。沉积的薄膜为非晶态，磁性非常柔软，具有很强的面内磁各向异性。我们发现在特定条件下制备的一些薄膜具有很弱的面外各向异性。在合适的热处理条件下，Nd2Felt；14&gt；B相晶化，c轴沿薄膜法线取向。我们将这种现象命名为自织构晶体生长，由于c轴是易磁化的方向，薄膜很容易垂直于薄膜平面磁化。该薄膜具有显著的永磁体特性：矫顽力大于15kOe，剩余磁通密度为9 kg，最大能量积(BH)_lt；max&gt；高达201MGOe。这种高的矫顽力可能是由于Nd2Fe14&Gt；B晶体的尺寸与单磁区尺寸一样大，c轴沿薄膜法向取向所致。我们认为，这种细小的微晶尺寸可能与自织构晶体生长中的形核密度有关。

项目成果

T. Okuda et al.: "Nd-Fe-B Thin Films of High Coercivity Prepared by Post-Annealing"Proc. Of the 16th Workshop on Rare-Earth Magnets and Their Applications, The Jpn. Inst. Of Metals. 393-402 (2000)

T. Okuda 等人：“通过后退火制备高矫顽力 Nd-Fe-B 薄膜”Proc。

T.Okuda et al.: "熱処理結晶化法によるNd-Fe-B径高保磁力薄膜の作製"電気学会マグネテイックス研究会資料. MAG-00-33. 33-38 (2000)

T. Okuda等人：“通过热处理结晶方法制备Nd-Fe-B直径高矫顽力薄膜”IEEJ Magnetics Study Group Material。

T. Okuda et al.: "Effect of Substrate Temperature on Perpendicular Magnetic Anisotropy of Nd-Fe-B Films Prepared by RF-Sputtering with Subsequent Heat Treatment"Trans. Magn. Soc. Jpn.. Vol. 2, No.2(To be published). (2002)

T. Okuda 等人：“基板温度对通过射频溅射和后续热处理制备的 Nd-Fe-B 薄膜的垂直磁各向异性的影响”Trans。

T.Okuda et al.: "Magnetic and Structural Properties of NdFeB Thin Film Prepared by Step Annealing"Abstract of 17^<th> Int.Colloq.on Magn.Films and Surfaces(Kyoto,2002). P2-45 (2002)

T.Okuda 等人：“通过逐步退火制备的 NdFeB 薄膜的磁性和结构特性”第 17 届 Int.Colloq.on Magn.Films and Surfaces 摘要（Kyoto，2002）。

T.Okuda et al.: "Nd-FeB Thin Films of High Coercivity Prepared By Post-Annealing"Proc.of 16^<th> Workshop on Rare-Earth Magnets and Their Applicastions, The Jpn.Inst.of Metals. 393-402 (2000)

T.Okuda 等人：“通过后退火制备高矫顽力的 Nd-FeB 薄膜”第 16 届稀土磁体及其应用研讨会论文集，日本金属研究所。