Low-Dimensional Forest-Like and Desert-Like Fractal Patterns Formed in a DDAN Molecular System  

作　　者：蔡金明 鲍丽宏 郭伟 蔡莉 郇庆 连季春 郭海鸣 王科志 时东霞 庞世谨 高鸿钧 

机构地区：[1]Beijing National Laboratory of Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100080 [2]Department of Chemistry, Beijing Normal University, Beijing 100871

出　　处：《Chinese Physics Letters》2007年第10期2918-2921,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 90406022. the Hi-Tech Research and Development Programme of China under Grant No 2004AA302G11, and the National Basic Research Programme of China under Grant No 2006CB921305.

摘　　要：Two kinds of forest-like and desert-like patterns are formed by thermal evaporation of 4-dicyanovinyl-N, Ndimethylamino-1-naphthalene （DDAN） onto SiO2 substrates. Based on thermal kinetics of the molecules on the substrate the transformation between the forest and desert patterns is due to two factors. The first one is the diffusion length, which is related to the deposition rate, the diffusion potential energy barrier and the substrate temperature. The second one is the strong interaction between the two polarity chemical groups of the molecules, which is beneficial to the formation of branches. Totally different patterns are also found on mica substrates, and are attributed to the anisotropic diffusion and the stronger interaction between DDAN molecules and the mica surface.Two kinds of forest-like and desert-like patterns are formed by thermal evaporation of 4-dicyanovinyl-N, Ndimethylamino-1-naphthalene （DDAN） onto SiO2 substrates. Based on thermal kinetics of the molecules on the substrate the transformation between the forest and desert patterns is due to two factors. The first one is the diffusion length, which is related to the deposition rate, the diffusion potential energy barrier and the substrate temperature. The second one is the strong interaction between the two polarity chemical groups of the molecules, which is beneficial to the formation of branches. Totally different patterns are also found on mica substrates, and are attributed to the anisotropic diffusion and the stronger interaction between DDAN molecules and the mica surface.

关 键 词：SCANNING-TUNNELING-MICROSCOPY THIN-FILM GROWTH FLUORESCENT-PROBES BEAMDEPOSITION NANOMETER-SCALE AGGREGATION DERIVATIVES FORCE 

分 类 号：O56[理学—原子与分子物理]