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We study electrical properties of metal/Ge contacts with an atomically controlled interface, and compare them with those with a disordered one, where atomically controlled interfaces can be demonstrated by using Fe3Si/Ge(111) contacts. We find that the Schottky barrier height of Fe3Si/n-Ge(111) contacts is unexpectedly lower than those induced by the strong Fermi-level pinning at other metal/n-Ge contacts. For Fe3Si/p-Ge(111) contacts, we identify clear rectifying behavior in I-V characteristics at low temperatures, which is also different from I-V features due to the strong Fermi-level pinning at other metal/p-Ge contacts. These results indicate that there is an extrinsic contribution such as dangling bonds to the Fermi-level pinning effect at the directly connected metal/Ge contacts.

Computer simulation is carried out for microphase-separated diblock copolymers under applied shear deformation. A mesophase of hexagonally ordered cylindrical domains is considered, and shear strains are applied perpendicular to the cylinder axes. Rheological responses and structural changes of the system under oscillatory and step-shear strains are studied by using a cell dynamic approach. For small strains, the usual behavior of ordered viscoelastic solids is seen, while for large strains, anomalous behavior is observed, including (i) in the case of oscillatory shears, a nonlinear stress response which is out of phase with the applied strain in the low frequency limit and (ii) in the case of step-shear, a double stress relaxation process in which the stress first approaches a pseudoequilibrium value and then much later relaxes further toward the final equilibrium value. This anomalous behavior is shown to be due to the slippage of lattice planes.

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