[(Fe/Pt/Fe)/Ag]_n多层膜低温合成分离的L1_0相FePt纳米颗粒  

Formation of L1_0-FePt nanoparticles with the precursor of [(Fe/Pt/Fe)/Ag]_n multilayer at lowered annealing temperature

作　　者：竺云[1] 蔡建旺[1] 

机构地区：[1]中国科学院物理研究所磁学国家重点实验室,北京100080

出　　处：《物理学报》2005年第1期393-396,共4页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :5 0 2 710 81)资助的课题~~

摘　　要：制备了 [(Fe Pt Fe) Ag]n 多层膜 ,研究了不同温度退火后的微结构和磁特性 .实验结果表明温度高于 4 0 0℃退火后 ,样品开始形成L10 相的FePt纳米颗粒与Ag基体的复合结构 .ΔM曲线的测量表明FePt颗粒之间不存在交换作用 ,非常清楚地说明非磁基体Ag有效地隔离了FePt磁性颗粒 .有序相的低温合成可能和多层膜结构所造成的界面扩散以及Ag层引入的界面缺陷有关 ,同时 ,Ag原子较强的迁移性以及FePt与Ag之间表面自由能的显著差异 。Microstructure and magnetic properties of [ (Fe/PL/Fe)/Ag](n) multilayer films after ex situ annealing at various temperatures have been investigated. The results indicate that, the multilayer starts to transform to isolated L1(0)-FePt nanoparticles embedded in Ag matrix after annealing at temperatures above 400degreesC. The formation of the face-center tetragondal (fct) phase at relatively low temperatures seems to relate with the rapid diffusion at the interface of 'Fe/Pt/Fe' and the defects caused by Ag, and the high migration speed as well as the much smaller surface free energy of Ag leads to the-separation of FePt nanoparticles, which is evidenced by the result of DeltaM measurements.

关 键 词：多层膜 原子 低温合成 交换作用 纳米颗粒 磁特性 表面自由能 基体 磁性颗粒 成分 

分 类 号：O484[理学—固体物理]