NiAl(110)和Cu-Al(111)合金表面生长超薄氧化铝膜的畴界和厚度的STM研究

Domain boundaries and thicknesses of ultrathin alumina films on NiAl(110) and Cu-Al(111) studied by STM

利用低温超高真空扫描隧道显微术研究了在NiAl(110)和Cu-Al(111)合金衬底上氧化生长的超薄氧化铝膜的畴界和厚度。在这两种氧化铝薄膜上均观察到两种不同类型的畴界:反相畴界(antiphase domain boundary)和反射畴界(reflection domain boundary)。结果显示Cu-Al(111)表面上的氧化铝薄膜的反相畴界数目相对较少;在NiAl(110)表面形成了双层氧化铝薄膜,而在Cu-Al(111)表面形成的是单层的氧化铝薄膜;厚度差异与衬底表面铝的含量及生长条件有关。

By oxidizing NiAl（110） and Cu-Al（111）,ultrathin alumina films were grown and their structures were investigated by ultra-high vacuum scanning tunneling microscopy（UHV-STM）.On both alumina films,two types of domain boundaries,i.e.,antiphase domain boundary and reflection domain boundary,are observed.However,the alumina film on Cu-Al（111） shows less numbers of antiphase domain boundaries in comparison with the case on NiAl（110）.STM results reveals that the alumina films on NiAl（110） shows the thickness of double-layer,while on Cu-Al（111） it corresponds to one single layer.Furthermore,we find that the thickness difference may relate to the aluminum concentration of the substrate surfaces as well as the growth conditions.