薄膜生长基底对FeS_2晶体取向的影响  

Effect of substrate structures on crystal orientation of the FeS_2 thin films

作　　者：刘艳辉[1] 孟亮[1] 张秀娟[1] 

机构地区：[1]浙江大学

出　　处：《材料研究学报》2004年第4期373-379,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金50071056资助项目

摘　　要：用Fe膜硫化法制备FeS2薄膜,分析了基底对FeS2薄膜晶体结构和位向分布的影响.结果表明,改变基底晶体的类型能够在一定程度上控制FeS2薄膜的晶体位向分布.FeS2薄膜在Si(100)、Si(111)和Al基底上可获得(200)方向的择优取向,在TiO2基底上可同时获得(200)及(220)择优取向,非晶玻璃基底对位向分布影响不明显.不同的基底与Fe薄膜的界面错配度不同,可改变薄膜晶体位向的分布,导致晶格畸变程度和晶粒尺寸的变化.当基底为非晶结构或界面的错配度较大时,FeS2晶体的取向分布主要受表面能和晶粒优先生长方向的控制,薄膜具有较小的晶格畸变和较细的晶粒;当基底为晶态并且界面错配度较小时,FeS2晶体取向的分布除受表面能及晶粒优先生长方向控制外,还受界面应变能的控制,此时薄膜易形成较大的品格畸变和粗晶粒.Polycrystalline FeS2 thin films were prepared by annealing the iron films in sulfur atmosphere. The crystal structure was determined and the orientation texture was discussed for the FeS2 films prepared on the substrates with different structures. The results show that the texture distribution of the film can be controlled in a certain extent using the substrate with different crystalline types. The FeS2 films prepared on the substrates Si(100), Si(111) and Al have only one preferred orientation (200), while those on the microcrystalline TiO2 substrates share two preferred orientations (200) and (220). There is an insignificant effect of amorphous glass substrates on orientation distribution in the film growth. Various substrates induce different interfacial mismatch between the film and substrate, and result in the changes of lattice distortion degree, grain size and texture distribution. The film surface energy and natural orientation of grain growth mainly dominate the resultant distribution of crystal orientation and induce small lattice distortion and fine grains in the film if the substrate is amorphous or has high interfacial mismatch. Besides the film surface energy and natural orientation of grain growth, the interface strain energy participates in the domination to the resultant distribution of crystal orientation and tends to induce strong lattice distortion and coarse grains if the substrate is crystalline and has low interfacial mismatch.

关 键 词：无机非金属材料 FES2薄膜 Fe膜硫化法 晶体取向 表面能 界面应变能 

分 类 号：TN304[电子电信—物理电子学]