Reconstruction dependent orientation of Ag(111) films on Si(001)

The growth of Ag on 4°-misoriented, single-domain Si(001) surfaces at 130 K yields continuous and epitaxial overlayers with a (111) orientation. The close-packed rows of Ag atoms are parallel to the (2×1) dimer rows and run perpendicular to the step edges. The dimer orientation can be rotated by 90° by inducing a (3×2) reconstruction on the Si(001) surface. Again, single-crystal Ag(111) films are obtained; however, their in-plane orientation is now rotated by 90°. In this case, the close-packed rows of Ag atoms are aligned parallel to the step edges.