Fe/Ag复合团簇镶嵌薄膜微观结构和磁性的研究

STRUCTURE AND MAGNETIC PROPERTIES OF Fe/Ag CLUSTER EMBEDDED FILM

提出了蒸发气体聚集（ＥＧＡ）共沉积制备复合团簇镶嵌薄膜的新方法，并分别在方华膜和单晶Ｓｉ（１１１）衬底上制备了系列Ｆｅ／Ａｇ磁性复合团簇镶嵌薄膜样品，对所制备的样品进行了透射电镜分析，Ｘ射线能谱分析和振动样品磁强计磁性测量。结果表明，样品中Ｆｅ、Ａｇ形成了相分离，为ｆｃ结构的Ａｇ和ｂｃｃ结构的Ｆｅ多晶共存形态；对应于不同大小的Ｆｅ团簇样品，与块材相比，Ｆｅ团簇的晶格常数呈现出不同程度的收缩，当团簇大小为８ｎｍ时，其晶格收缩量为５．７％。在８５Ｋ３００Ｋ的测量温度范围内，样品仍表现出铁磁性；随着测量温度的降低，样品饱和磁化强度逐渐接近于αＦｅ块材相应值。在低温时，样品矫顽力远远高于αＦｅ块材相应值，而随着测量温度的升高，样品矫顽力逐渐降低，但在室温时仍略高于αＦｅ块材值。

Series of Fe/Ag cluster embedded film were prepared on farmvar foil or single crystal Si(111) by Evaporation Gas Aggregation (EGA) co deposition in this paper. TEM analysis shows that fcc Ag and bcc Fe coexist in as deposited samples, Fe clusters being 8nm in average diameter are well encapsulated in Ag matrix. More detailed analysis shows that, compared with that of bulk α Fe, the lattice constant of Fe clusters decreases in different degree depending on clusters size,the shrinking amount is 5.7% for Fe cluster 8nm in size, magnetic measurement indicates that samples show ferromagnetic behavior and their saturation magnetization increase with decreasing of testing temperature. At lower temperature, the coercivity is much higher than that of bulk α Fe, and it decreases with increasing of testing temperature.