Self-assembled growth of MnSi∼1.7 nanowires with a single orientation and a large aspect ratio on Si(110) surfaces

MnSi-1.7 nanowires (NWs) with a single orientation and a large aspect ratio have been formed on a Si(110) surface with the molecular beam epitaxy method by a delicate control of growth parameters, such as temperature, deposition rate, and deposition time. Scanning tunneling microscopy (STM) was employed to study the influence of these parameters on the growth of NWs. The supply of free Si atoms per unit time during the silicide reaction plays a critical role in the growth kinetics of the NWs. High growth temperature and low deposition rate are favorable for the formation of NWs with a large aspect ratio. The orientation relationship between the NWs and the reconstruction rows of the Si(110) surface suggests that the NWs grow along the direction of the silicon substrate. High-resolution STM and backscattered electron scanning electron microscopy images indicate that the NWs are composed of MnSi-1.7.