J.Zhanga, S.H.Chob, and J.M.SeobaDepartment of Physics, Yunnan University, Kunming 650091,P.R.China bDepartment of Physics, Chonbuk National University, Chonju 561-756, Korea Growth and disorder of Ag nanowires on Si(5 5 12)-21 surface

Side view of the silicon crystal lattice between the (001) and (111) planes

Structural model of Si(5 5 12)-21 surface

STM images of clean Si(5 5 12)-21 surface Reconstruction: Cooling down at ~2 C /sec. from 700 C to RT Filled-state STM image: I= 0.6nA, Bias = -2.5V, Rotation= 30 Topography 200200[ 1 1 0 ][ 6 6 5 ]21 unit cell 0.775.35nmError signal 200200[ 6 6 5 ]-chainsTetramer

3-D STM image of clean Si(5 5 12)-21(5 5 12) = 2(3 3 7) + (2 2 5) = (3 3 7) + (7 7 17)

Steps and kinks on Si(5 5 12)-21 surface Error signal: 1000 1000 Error signal: 350 350[ 1 1 0 ][ 6 6 5 ]Si(1 1 3)Lower terraceUpper terraceStep AStep BStep A

Wide Si(7 7 17) domain parasitic on Si(5 5 12) surface

Comparison of topography and error signal images of Si(7 7 17)

Comparison of clean Si(7 7 17) and Ag:Si(7 7 17) systemdisorder

STS of Ag nanowires on Si(5 5 12)-21 surface

Si(111)-77 surface measured by STM.

STM image and simulation for Ga6/Si(111)-77 surface+1.6 eVJ.F.Jia, Phys. Rev. Lett.

5000 X 5000 5000 X 5000 4277 X 4277 5000 X 5000Steps on clean Si(5 5 12)-21 surface

Steps on clean Si(5 5 12)-21 surface

Steps and kinks on clean Si(5 5 12)-21 surface

Step flows on clean Si(5 5 12)-21 surface

Si(001)

Kinetics: Layer-by-Layer GrowthDiffusionNucleationGrowth- High Flux - Low Temperature - Low Step Density

Step flow: A 2D analog of 3D growth

Breakdown of Step Flow Growth

SummaryNano Scale --- minimizing elastic strain energyself-organization of steps (quantum wires)and islands (quantum dots)Ag nanowires on Si(5 5 12)-21 surface form along tetramer rows where the binding energy is relatively low1D Ag nanowires with disorder structuers show metal-insulator transition (Anderson effect)