Cu 2 Sb is known as a promising anode material for a lithium ion battery due to its good cycle performance and large volumetric capacity. In the present study we aimed to construct the ternary phase diagram for the Li-Cu-Sb system to elucidate the reaction mechanism upon charge-discharge reaction. In this procedure, a new intermediate phase of LiCuSb with a half-Heusler-type structure was found by combining experimental results with theoretical study. The obtained ternary phase diagram accounted for the electrochemical lithiation of Cu 2 Sb by the following three-step reaction: (1) Li incorporation into Cu 2 Sb formed LiCuSb accompanying extrusion of Cu metals, (2) the solid solution process of Li 1+x CuSb (0 e x < ∼0.5) with a Heusler-type structure was followed, and then (3) by further lithiation Li 3 Sb was formed with Cu extrusion as a threephase coexistence reaction. The irreversible capacity at the first cycle was assigned to the structural phase transition from Cu 2 Sb to LiCuSb and Cu. Thus, the present study suggested that the intermetallic compounds with a Heusler-type structure have a promising potential as the anode material for a lithium ion battery with a long life and a large capacity.

The local crystal structure of a spinel-type solid solution, LiCr y Mn2 - y O4 has been studied by molecular dynamics (MD) and extended X-ray absorption fine structure (EXAFS), respectively. The MD simulation was carried out using a partially ionic model, and the relevant potential parameters were optimized. The simulated compositional dependence of lattice parameters and thermal expansion coefficients were found to be reproducible with experimental values. From the simulation results, the pair correlation function curve for Mn4+−O in LiMn3+Mn4+O4 was broader than that in LiCr3+Mn4+O4. This indicates that the local distortion of the lattice is suppressed by substituting a Cr3+ ion for a Mn3+ ion. Similar results were also obtained by EXAFS measurement. The force constant k derived from MD simulation increases by substituting Cr3+ ion for Mn3+ ion, and this corresponds to the strengthening of the bond between a transition metal cation and an oxide ion.

This paper deals with fundamental research on heat transfer characteristics inside a cooling configuration designed for an ultra-high temperature turbine nozzle. The cooling configuration adopted in this study integrates impingement cooling and pin cooling devices into one body, aiming at the enhancement of the effective area for the impingement cooling. A large-scaled test model of this cooling system is constructed to measure its internal heat transfer distribution, where a number of pins are sandwiched between an impingement plate and a target plate. The target plate are provided with several air discharging holes. A focus of this study is on how the heat transfer characteristics depend on the effect of stand-off distance: a distance between these two plates. Ratios of the stand-off distance to the impingement hole diameter varies from 0.75 to 2.00. A transient measurement technique using narrow-banded thermochromatic liquid crystal (TLC) is employed to determine the heat transfer characteristics of the model. Numerical investigations using a commercial CFD code are also executed and those results are compared with the experimental data. It is accordingly found that the numerical results almost match the measurements. It is also shown that the addition of pins to the conventional impingement cooling system can produce about 50% increase in the effective cooling area.

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This paper deals with the reaction dynamics of phase transition for the electrochemical lithium insertion into Cu 2 Sb intermetallic compound. Electrochemical lithium insertion/removal, alternating current ͑ac͒ impedance technique, and electrochemical calorimetric measurement have been applied in this study. The electrochemical charge-discharge test indicated a large irreversible capacity at the onset of first charging ͑Li insertion͒, where a flat voltage plateau appeared around 0.7 V. In other instances, following cycles showed good reversibility. In addition, the voltage profiles of Ͼ0.7 V region after the second cycle showed higher than the one at the first cycle charging and clear solid solution manner. Thus, the difference of the electrochemical Li insertion mechanism between the first and following cycles caused irreversibility accompanying large electrochemical polarization. To explain the above phenomena, we assumed that the nucleation was rate determined at the onset of phase transition from tetragonal Cu 2 Sb to cubic Li 1+x CuSb. After the phase transition was completed, following cycles did not need to expend the formation of different phase nuclear, showing a good reversibility reaction. The reaction mechanism suggested above was supported by ac impedance and electrochemical calorimetric measurements.

Using reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD) and X-ray pole figure measurements, we evaluated the crystallinities of yttria-stabilized zirconia (YSZ) thin films as an intermediate layer for metal/ferroelectric/insulator/semiconductor-structure field-effect transistors (MFIS-FETs). A highly oriented YSZ film was grown on a Si(100) substrate by the vacuum evaporation method. The [100] axes of the YSZ crystals were aligned parallel to [100] axes of Si crystals in the plane. In addition, electrical characterizations of the highly oriented YSZ thin films on Si(100) were evaluated from current–voltage ( I–V ) and capacitance–voltage ( C–V ) measurements. The I–V measurement indicated a breakdown field of about 3 MV/cm (at I=1 nA/cm2). The C–V measurement results suggest that mobile ions were present in the YSZ films. Oriented perovskite PbTiO3 films were deposited on YSZ crystal and YSZ/Si(100) substrates by the digital chemical vapor deposition (CVD) method. These PbTiO3 films included many PbTiO3 grains with their [100] axes parallel to the [100] or [110] axis of YSZ crystals in the plane of the PbTiO3/YSZ interface.

We have constructed two types of picosecond time-resolved Raman spectrometers with near-infrared excitation. One system is based on a step-scan Fourier transform (FT) interferometer equipped with a Ge detector, and the other system is based on a dispersive spectrometer equipped with an InGaAs array detector. For the former system with pulsed Raman excitation, we have developed a new method of signal processing. This method does not require synchronization among laser pulses for Raman excitation, the stepping of the step-scan interferometer, and the sampling of the analog-to-digital converter. In spite of large fluctuation in the probe-pulse energy, the ordinary FT-Raman spectra of samples in the ground electronic state can be obtained with satisfactory signal-to-noise ratios by the former system. By the latter system, picosecond transient Raman spectra have been obtained from the first excited singlet (S 1 ) state of 9-phenylanthracene and the second excited singlet (S 2 ) state of all-trans-b-carotene by using 388-nm light for photoexcitation and 1064-nm light for Raman excitation.

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