用扫描隧道显微镜操纵Cu亚表面自间隙原子

在超高真空环境下使用扫描隧道显微镜研究了吸附有双甘氨肽分子的Cu(001)表面.在一定的 偏压条件下，针尖在该表面扫描后会形成纳米尺度的Cu团簇，这些团簇可以根据意愿排列成 字母或图形.团簇的高度同偏压、隧道电流以及时间等条件有密切关系.在室温下可以稳定存 在的团簇为制造纳米器件提供了技术上的可能性.实验结果表明，形成团簇的Cu原子不是来 自Cu衬底表面或是针尖.化学吸附在Cu表面的双甘氨肽分子，受到隧道电场的作用会在Cu表 面形成张应变场，Cu亚表面自间隙原子在张应变场作用下迁移到表面是形成团簇的原因. 关键词： 扫描隧道显微镜 纳米尺度Cu团簇 自间隙原子

The manipulation of Cu subsurface interstitial atoms with scanning tunneling microscope

In this paper, the Cu(001) surface covered with glycylglycine has been studied by scanning tunneling microscope(STM) under ultra_high vacuum condition. On that surface copper clusters in nanometer_scale, which could form alphabet or graph a t our wishes, may be produced by the scanning of STM under a certain bias voltag e condition. The height of these clusters has a close relation with bias voltage , tunnel current and time. It offers the opportunity to fabricate nanometer_scal e apparatus by these clusters due to their stability at room temperature. The ex perimental result shows that the copper atoms which form these clusters come fro m neither copper substrate surface nor STM tip. We think that the tensile stress field in the copper substrate is produced due to the chemisorbed glycylglycine molecule in tunnel electric field and it is the migration of copper subsurface i nterstitial atoms under that tensile stress field that causes the formation of c opper clusters.