The phonon frequencies of metallic ultrathin films were studied by the resonant acoustic-phonon spectroscopy using femtosecond pump-probe method. We excite and detect the acoustic-phonon resonances in the thin films thinner than 50 nm using the femtosecond light pulses. The pump light causes the phonon vibrations through the thermal expansion at the film surface. For the ultrathin films, the st...

The glass transition process gets affected in ultrathin films having thickness comparable to the size of the molecules. We observe systematic broadening of the glass transition temperature (T(g)) as the thickness of an ultrathin polymer film reduces below the radius of gyration but the change in the average T(g) was found to be very small. The existence of reversible negative and positive therm...

Well-ordered, thin oxide films have drawn some attention in recent years as suitable oxide supports for modeling highly dispersed metal catalysts at the atomic scale. It turned out, however, that ultrathin oxide films may exhibit interesting catalytic properties in their own right. In this review, we discuss phenomena specifically connected to ultrathin oxide films to explain and understand the...

For the first time we synthesized mesoporous CeO2 nanosheets with single-crystal-like, ultrathin and uniform-sized structures through the thermal decomposition of specially prepared intermediates of Ce(OH)CO3 nanosheets. The resulting single-crystal-like CeO2 porous nanosheets are only 2.4 nm thick, as measured by AFM. BET analysis indicated that the pores of the nanosheets were centered at 3.7...

One-dimensional gold nanowires (AuNWs) have attracted considerable interests because of their high aspect ratios, unusual physical properties and potential applications in nanoelectronics, photonics and sensors. The large anisotropy of AuNWs and their subsequent assembly ability make them especially important building blocks for the linkage of nanoscale electronics and molecular devices. Many s...

Growth of Mn on GaAs(100) is studied by photoemission and electron-energy-loss spectroscopy. %e find that the first layer of Mn grows on GaAs(100) in a two-dimensional mode, where about 10% of the Mn atoms take part in the chemical reaction with the substrate. The electronic structure of the ultrathin film of Mn is found to be very different from that of bulk a-Mn, and the possibility that magn...

Spin-polarized tunneling is investigated in magnetic tunnel junctions containing an ultrathin interfacial layer of Co:TiO magnetic semiconductor. The Co:TiO layers (0 to 1 nm thick) are inserted at the SrTiO Co interface in La Sr MnO SrTiO Co tunnel junctions. For all junctions we find a negative tunnel magnetoresistance, which decreases upon the insertion of Co:TiO , while the junction resista...

Ultrathin CoMn2O4 nanosheets supported on reduced graphene oxide (rGO) are successfully synthesized through a simple co-precipitation method with a post-annealing treatment. With the assistance of citrate, the free-standing CoMn2O4 ultrathin nanosheets can form porous overlays on both sides of the rGO sheets. Such a novel hybrid nanostructure can effectively promote charge transport and accommo...

A direct demonstration of defect generation in ultrathin silicon dioxide films due to the transport of holes through this layer is reported. These defects are observed only when the hole current to the cathode of the device exceeds the electron current to the anode. This condition is produced on p-channel field-effect transistors under negative gate-voltage-bias conditions with ultrathin gate o...

We report on the experimental study of an anomalous transmission effect in ultrathin metallic gratings, where the metal thickness is much thinner than the skin depth. In particular, incident transverse magnetic polarized waves are reflected while incident transverse electric polarized waves are transmitted. This anomalous effect is strongly dependent on the metal thickness and metal width. We s...