蒸发—气体—聚集制备的Co—Ag颗粒膜微观结构与巨磁电阻特性

基于溅射－气体－聚焦（ＳＧＡ）形成纳米金属颗粒的原理，提出了蒸发－气体－聚集（ＥＧＡ）共沉积制备Ｃｏ－Ａｇ颗粒膜的新方法，并利用该方法制备了系列Ｃｏ－Ａｇ颗粒膜样品，ＴＥＭ／ＥＤ分析表明；制备态样品Ｃｏ颗粒被Ａｇ原子所包裹，能有效地阻止颗粒的表面氧化与团聚，薄膜无需经过热处理即可形成Ｃｏ与Ａｇ的相分离，其结构为ｆｃｃ－Ｃｏ和ｆｃｃ－Ａｇ非均匀相多晶共存形态；与Ｃｏ大块材料相比，薄膜中Ｃｏ颗粒晶格常

MICROSTRUCTURE AND GIANT MAGNETORESISTANCE OF Co-Ag GRANULAR FILMS DEPOSITED BY EVXPORATION-GAS-AGGREGATION

A novel method, i.e. evaporation-gas-aggregation(EG co- deposition for the preparation of Co-Ag granular films is developed in this paper. TEM analysis shows that Co particles are wellencapsulated in Ag coatings and in polycrystal form with fee-Co and fee-Ag in as-prepared samples,in which surface oxidation and self-aggregation of Co particles could be avoided effectively. Comparedwith the bulk Co, the lattice constant of Co particles is shrinking in different degree depending on particlesize, and the shrinking amount is 7% for Co particles being sum in average diameter. Magnetoresistancemeasurement reveals that the samples show relative large giant magnetoresistance (GMR) at 300K, and theGMR increases with the decrease of particle size in the films.