Thürmer Konrad, Williams Ellen, Reutt-Robey Janice
Department of Physics, University of Maryland, College Park, MD 20742, USA.
Science. 2002 Sep 20;297(5589):2033-5. doi: 10.1126/science.297.5589.2033.
Growth of an ultrathin lead oxide layer causes massive changes in the shape of lead crystallites. The dynamics of this process was investigated with time-lapsed scanning tunneling microscopy. Pure lead crystallites proved extremely resistant to oxidation. Once nucleated by surface impurities, monolayer films of lead oxide grew readily on lead (111) microfacets in an autocatalytic process. The anisotropic growth of orthorhombic lead oxide films (massicot structure) was most rapid along the direction of weakest lead-oxygen bonding, which suggests that the growth edge autocatalyzes oxygen dissociation by providing proximal sites for oxygen dissociation and attachment.
超薄氧化铅层的生长会导致铅微晶形状发生巨大变化。利用延时扫描隧道显微镜对该过程的动力学进行了研究。纯铅微晶被证明对氧化具有极强的抗性。一旦被表面杂质成核，氧化铅单层膜就在铅（111）微面上通过自催化过程轻松生长。正交晶系氧化铅膜（密陀僧结构）的各向异性生长沿铅 - 氧键最弱的方向最为迅速，这表明生长边缘通过为氧解离和附着提供近端位点来自动催化氧解离。
