Atomic layer engineering of perovskite oxides for chemically sharp heterointerfaces.

Atomic layer engineering enables fabrication of a chemically sharp oxide heterointerface. The interface formation and strain evolution during the initial growth of LaAlO(3) /SrTiO(3) heterostructures by pulsed laser deposition are investigated in search of a means for controlling the atomic-sharpness of the interface. This study shows that inserting a monolayer of LaAlO(3) grown at high oxygen pressure dramatically enhances interface abruptness.

Temperature-dependent Raman spectroscopic study of the nematic liquid crystal 4-n-pentyl-4'-cyanobiphenyl.

The spectral behaviors of 4-n-pentyl-4'-cyanobiphenyl (5 CB) have been studied by means of temperature-dependent Raman spectros-copy in the range between --70 and 70 degrees C. The nu(C identical with N) bands in the Raman spectra were found splitting below the transition temperature from the solid to the nematic liquid crystalline phase at approximately 24 degrees C, suggesting the existence of solid crystalline polymorphism. The interfacial structures of 5 CB on metal plate surfaces have been reexamined by surface-enhanced Raman scattering (SERS) at different temperatures.