Search

The Ho/Si(1 1 1)-1×1 and H–Ho/Si(1 1 1)-1×1 surfaces have been investigated by low energy electron diffraction I–V curve analysis. Several structural models have been tried and the optimum structure has been obtained using a combination of search methods. In the case of the Ho/Si(1 1 1) surface, Ho atoms sit on T4 sites of the Si(1 1 1) near bulk-like layer and are located underneath a Si bilayer which is rotated 180° with respect to the substrate Si layers. This is the same structure as proposed by medium-energy ion scattering. In the case of the H–Ho/Si(1 1 1)-1×1 surface, Si atoms in the surface bilayer have normal stacking and are located above the same lateral position as the topmost bulk layer.

The first measurement of two-nucleon pion absorption in 4 He at 1 GeV/ c has been performed at the KEK 12 GeV proton synchroton. Both the (π + , pp) and (π + , pn) modes were measured and clearly identified, even at this energy. An isospin dependence was obtained which was different from that in the Δ-energy region.

The first measurement of the invariant cross sections and polarizations of Λ hyperons produced by the reaction π − 6 Li → ΛX at 4 GeV /c in the backward angular region ( 70° lab ) has been done. In the measured region the production with free nucleons was kinematically forbidden. All the experimental results are reproduced by a quark-parton model calculation.

Crystals of electrodeposited zinc films were observed directly and indirectly by metallurgical microscopy. The quantity of electricity used in the deposition was 18 C cm -2 , the current density ranged from 1.0 to 10.0 A dm -2 and the magnetic flux density ranged from 0 to 0.125 T. The temperature of the test solutions ranged from 5 to 60 °C. The growth of dendrites was inhibited by the magnetic fields. Compared with the efficiencies in the absence of the magnetic field, the cathodic efficiency increased by about 5% – 10% and the anodic efficiency decreased by about 5% – 10%.

The iron oxide/ n -Si heterojunction electrode was investigated as a possible efficient photoanode with the iron oxide prepared under various conditions. The oxide structure was studied by RBS (Rutherford backscattering spectrometry) and XPS (X-ray photoelectron spectroscopy) techniques and the correlation between photocharacteristics and its oxide structure was discussed. The iron oxide prepared by thermal oxidation and reactive-evaporation methods. The photocurrent in a 0.2 mol dm −3 KOH solution was found to strongly depend on the preparation of the iron oxide. The reactive-evaporated Fe 2 O 3 / n -Si electrode showed the most effective characteristics of photoresponse and the 60 min thermally oxidized Fe 2 O 3 / n -Si electrode gave the best results in the thermally oxidized oxide system. The compositional analysis by RBS indicated that the oxide is formed stoichiometrically as Fe 2 O 3 and that small amounts of a heavy-mass and a tungsten impurity are present in the thermally oxidized and the reactive-evaporated oxides, respectively. The XPS analysis of the chemical state of the iron in the oxide showed that the chemical state of the iron oxide formed by thermal oxidation varies as a function of depth and that the iron oxide formed by reactive- evaporation is in a almost constant chemical state throughout the film.