团簇大小对Fe－Ag和Co－Ag包埋团簇形貌及结构的影响

Size Effection on Morphology and Structure of Fe Ag and Co Ag Embedded Clusters

利用蒸发－气体－聚集（ＥＧＡ）共沉积方法，在有方华膜的电镜载网上制备了Ｆｅ－Ａｇ及Ｃｏ－Ａｇ系列纳米磁性包埋团簇，通过控制蒸发电流等沉积条件，获得了不同团簇大小的样品。ＴＥＭ／ＥＤ分析表明，当样品中Ｆｅ（Ｃｏ）团簇尺寸较小时（分别为１０ｎｍ和２０ｎｍ），样品形貌表现为Ｆｅ（Ｃｏ）团簇弥散地分布在Ａｇ膜基质中，形成了Ａｇ膜对Ｆｅ（Ｃｏ）团簇的分隔与包埋；其结构分别为Ｆｅ、Ａｇ多晶和Ｃｏ、Ａｇ多晶共存的形态。而当Ｆｅ（Ｃｏ）团簇尺寸较大时（分别为９０ｎｍ和５０ｎｍ），样品中Ａｇ原子也相对聚集，Ａｇ膜没有形成对Ｆｅ（Ｃｏ）团簇的完全包裹，在形貌上Ｆｅ－Ａｇ样品呈现为“串状”，Ｃｏ－Ａｇ样品呈现为“花瓣状”；

Nanometer size Fe Ag and Co Ag magnetic embedded clusters are produced by Evaporation Gas Aggregation(EGA)co deposition on formvar foil.TEM morphology investigation show that Fe(Co)clusters are dispersed in Ag matrix while Fe(Co)clusters being smaller in size,but it was not well achieved while Fe(Co)being larger in size,which show a “string shape”in Fe Ag sample and a“petal shape”in Co Ag sample.TEM electron diffraction show that Fe(Co)clusters and Ag coatings are in multiple crystal form in the former case,and in amorphous form in the later case.