Nd_(28)Fe_(66)B_6/Fe_(50)Co_(50)双层纳米复合膜的结构和磁性  

Preparation and magnetic properties of nanocomposite Nd_(28)Fe_(66)B_6/Fe_(50)Co_(50) bilayer films

作　　者：敖琪[1] 张瓦利[1] 张熠[1] 吴建生[1] 

机构地区：[1]上海交通大学,高温材料与高温测试教育部重点实验室,上海200030

出　　处：《物理学报》2005年第10期4889-4893,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批号:50071035);上海市自然科学基金(批号:02ZE14054)资助的课题.~~

摘　　要：利用磁控溅射法制备了Nd28Fe66B6/Fe50Co50双层纳米复合磁性薄膜,研究了其结构和磁性.经873K退火处理15min后,利用x射线衍射仪测定薄膜晶体结构,采用俄歇电子能谱仪估算薄膜厚度和超导量子干涉仪测量其磁性.磁性测量表明,1)该系列薄膜具有垂直于膜面的磁各向异性.从起始磁化曲线和小回线的形状特征可知,矫顽力机制主要是由畴壁钉扎控制.2)对于固定厚度(10nm)层的硬磁相Nd-Fe-B和不同厚度(dFeCo=1—100nm)层软磁相FeCo双层纳米复合膜,剩磁随软磁相FeCo厚度的增加快速增加,而矫顽力则减少.当dFeCo=5nm时,最大磁能积达到160×103A/m.磁滞回线的单一硬磁相特征说明,硬磁相Nd-Fe-B层和软磁相FeCo层之间的相互作用使两相很好地耦合在一起.剩磁和磁能积的提高是由于两相磁性交换耦合所致.The nanocomposite Nd28Fe66 B6/Fe50 Co50 bilayer films with Mo underlayer and overlayer have been fabricated on Si substrates. All the samples prepared have perpendicular anisotropy and the hysteresis loops are simple single loops for fixed Nd- Fe-B layer thickness （10nm） and different FeCo layer thickness （ dFeCo = 1-100nm）. The shape and the behavior of the initial loops and the minor loops suggest that wall pinning is the dominant coereivity mechanism in these films. The magnetization of these samples is found to increase with increasing FeCo layer thickness for a fixed Nd-Fe-B layer thickness and the coereivity of films decrease with increasing FeCo layer thickness. The sample of maximum energy product is 160×10^3A/m for dFeCo = 5nm at room temperature. The enhancement of the remanenee and energy products in nanoeomposite bilayer films is attributed to the exchange coupling between the magnetically soft and hard phases.

关 键 词：Nd-Fe-B/FeCo双层纳米复合膜 交换耦合 磁性增强 纳米复合膜 磁性薄膜 晶体结构 ND-FE-B 超导量子干涉仪 俄歇电子能谱仪 矫顽力机制 

分 类 号：O484[理学—固体物理]