退火温度对Nd_2Fe_(14)B/α-Fe磁性多层膜中相形成的影响  

Influence of annealing temperature on the phase transformation in the Nd_2Fe_(14)B/α-Fe nanocomposite mulitilayer films

作　　者：陈立军[1] 贺连龙[1] 刘伟[1] 张志东[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家(联合)实验室

出　　处：《材料研究学报》2004年第2期119-122,共4页Chinese Journal of Materials Research

基　　金：国家自然科学基金 50171068

摘　　要：通过TEM和HRTEM对比研究了软磁层厚度为2.5 um的Nd_2Fe_(14)B/α-Fe型多层膜的显微结构.结果表明,在退火前的多层膜中Fe层为多晶,硬磁相以非晶的状态存在;在600℃以上退火后软磁层消失,生成的Nd_2Fe_(14)B型相被固定在硬磁层内;625℃退火后发现有Nd_2Fe_(17)相在硬磁层中析出,表明在多层膜退火过程中,退火温度对相转变的影响比退火时间的影响更大.Nd_2Fe_(17)相的析出可能是高温退火后磁性能下降的主要原因.Microstructure of Nd_2Fe_(14)B/α-Fe-type multilayer films annealed at 600℃ for 5 min and annealed at 625℃ for 1 min with the same thickness of α-Fe layers (2.5 nm) have been investigated by TEM and HRTEM. The result showed that α-Fe nano-grains formed in Fe layers in the as-sputtered film. however. the hard magnetic phase remained amorphous state. When the annealing temperature was higher than 600℃, Nd_2Fe_(14)B type phases formed, the α-Fe layers were devoured by the hard magnetic layers, and Nd_2Fe_(17) phases were found in another multilayer film annealed at 625℃. It implied that the annealing temperature played a more important role in the phase transformation than the annealing time. The decrease of magnetic properties maybe resulted from the separating out of Nd_2Fe_(17) phase.

关 键 词：金属材料 纳米复合永磁材料 磁性多层膜 微观结构 交换耦合 高分辨观察 

分 类 号：TM271[一般工业技术—材料科学与工程]