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The establishment of a reliable method for the growth of bulk In–Ga–Zn–O single crystals is important not only to investigate the fundamental and peculiar properties specific to this material but also for its development for novel functional devices. Large bulk single crystals of InGaZnO4 have been successfully grown using an optical floating zone method under a flow of dry-air at high-pressure. The stoichiometric InGaZnO4 single crystals were obtained at a gas pressure of 0.9 MPa using a feed rod with a Zn-rich composition, where the lattice constants are a = 3.2990(4) A and c = 26.018(3) A as the hexagonal expression for the rhombic system (space group Rm, No. 166). The as-grown single crystals exhibit a blueish colour, but become transparent after annealing in oxygen. Upon post-annealing, the carrier density, the conductivity in the ab-plane and the mobility at room temperature changes in the range from ∼1020 to ∼1017 cm−3, from ∼2000 to ∼1 S cm−1, and from ∼100 to ∼10 cm2/(Vs), respectively. In addition, we found that the conductivity along the c-axis is much lower than that of the ab-plane in InGaZnO4 single crystals, and that the anisotropy increases with decreasing carrier density.

The aim of osteoporosis treatment is to prevent future fractures. Although concurrent treatment has been used very frequently for osteoporosis in clinical practice, there are no data on accurate and verified effectiveness of concurrent treatment for fracture prevention in patients with osteoporosis. To clarify the clinical usefulness of concurrent treatment, the Japan Osteoporosis Society has authorized the establishment of the A-TOP (Adequate Treatment of Osteoporosis) research group. The objective of this research is to establish a design for a clinical trial to prove whether concurrent treatment using both alfacalcidol (1-alpha-hydroxycholecalciferol) and alendronate is more effective as compared to treatment using alendronate alone in terms of fracture prevention. The present study was named JOINT (Japanese Osteoporosis Intervention Trial) and is based on a method using national, prospective, randomized, open-labeled, blinded endpoints focusing on postmenopausal osteoporosis with a high risk for fracture. The patients were mainly selected by practitioners and allocated randomly by a central registration system into two groups, of which one received 5 mg/day of alendronate alone, and the other received 1 μg/day of 1-alpha-hydroxycholecalciferol (alfacalcidol) in addition to the alendronate. The endpoints focused primarily on fracture prevention, and the patients' quality of life (QOL) and change in body height, as well as adherence and the adverse events of the treatments were evaluated secondarily. To obtain sufficient statistical power in the events during a 2-year observation period, the patients who are expected to have higher risk were selected to participate in this study, and it was decided that the final plan would involve 890 patients per group (two-sided alpha = 0.05, power = 0.8). Data collection began in November 2003. Correspondence regarding the registration of the investigator and the progress of the study was conducted through a web system from the Public Health Research Foundation to practitioners.

Microcrystalline silicon carbide (@mc-SiC) has several applications, such as solar cells, light-emitting diodes and as optical coating for solar cells. Hydrogenated amorphous silicon carbide (a-SiC:H) grows by plasma enhanced CVD, even under hydrogen diluted conditions. High concentration of atomic hydrogen from catalytic CVD could promote lower temperature growth of @mc-SiC under the same conditions as a-SiC:H without plasma. In the present study, @mc-SiC films have been successfully grown by catalytic CVD (hot-filament catalysis) from monomethylsilane and hydrogen on (100) silicon substrates maintained at 300^oC. The optimal chamber pressure is 1.0Torr and the optimal concentration of monomethylsilane in the hydrogen carrier gas is 1%. FTIR spectra of films obtained under these conditions show strong Si-C peaks.

Films of a-SiC:H grown on Si single crystal (1 0 0) by plasma-enhanced chemical vapor deposition (PECVD) are analyzed by Fourier transform infrared (FTIR) spectroscopy. PECVD is performed using a single monomethylsilane (CH3SiCl3) source with hydrogen carrier gas. The hydrogen bond content of the films is determined from the FTIR spectra and compared with the carbon and silicon bond contents as an investigation of the growth process during the atom incorporation phase. The silicon bonding environment is also investigated based on the shift of the FTIR peak of Si–C and Si–H bonds. It is found that the hydrogen bonds of the films is proportional to the square of plasma power density, explainable as due to a combination of two one-step reactions producing non-emissive atomic hydrogen and SiH2. The shift of the SiHn ( n = 1 , 2 ) peak reveals that the atoms nearest Si in the film are replaced by Si or H atom from C in CHn with increasing hydrogen content. A scheme for film growth in this system is then proposed based on the present and previous findings.

Proceedings of the Conference on Spectroscopies in Novel Superconductors, Break-junction tunneling data are reported in Bi2Sr2CaCu2O8+δ over a wide range of hole concentration from underdoped to overdoped. The strong conductance peaks in the superconducting state reveal a single gap consistent with d-wave symmetry. In addition, sharp dips are observed at a voltage, Ω/□, measured with respect to the gap edge. These features are shown to be reproduced in other junction types from the literature including atomically resolved STM and □-axis mesas, establishing their intrinsic character. Trends are observed with doping and temperature which link the dip to the resonance spin excitation and indicate that the quasiparticles are strongly coupled to this mode.

Films of a-SiC:H were deposited on Si (1 0 0) substrates by plasma chemical vapor deposition from monomethylsilane. The growth kinetics is discussed on the basis of in situ optical emission spectroscopy (OES) and absorption spectroscopy. The film has near-stoichiometric composition and the growth rate increases slightly with increasing plasma electron density. The OES spectra indicate the presence of H, H 2 , and SiH, and an SiH 2 band is observed in the absorption spectra. It is considered that the SiH 2 concentration determines the growth rate. The spatial distribution of atomic hydrogen and SiH according to OES spectra indicates that the reaction species in the plasma reach the substrate by diffusion.

A comparison of two kinds of source materials is made with regard to the growth kinetics of hydrogenated amorphous silicon carbide films using the RF plasma CVD system with parallel electrodes. The two kinds of sources, methyltrichlorosilane and monomethylsilane, are molecules that include one atom each of carbon and silicon. They are used with a hydrogen carrier gas. In the methyltrichlorosilane–hydrogen system, a possible precursor to silicon carbide is SiCl 2 , and the silicon/carbon ratio of the films can be greatly changed by adjusting the plasma power. In the monomethylsilane–hydrogen system, SiH 2 is the rate-determining species, and the silicon/carbon ratio of the films can be slightly changed by adjusting the plasma power. The optical emission spectroscopy (OES) intensity distribution suggests that the precursor in both cases migrates to the substrate from the plasma sheath by diffusion.

Rapid increase in applications of the electromagnetic waves in the terahertz frequency range requires new techniques to obtain continues-wave terahertz radiation sources. It is shown that rectangular shaped mesa structure from Bi2Sr2CaCu2O8+d (Bi2212) is a good source for generation of terahertz radiation. In this study, we have fabricated triple mesa structures using e-beam lithography and argon ion beam etching techniques. Our aim is to find the critical current density dependence of mesa area to obtain maximum emission power for the terahertz radiation.

We work on a frequency tunable solid state device to meet the needs of continuous, coherent, powerful terahertz emission sources that fill practically important terahertz gap. High temperature superconducting (HTS) coherently oscillating Josephson junctions in Bi 2 Sr 2 CaCu 2 O 8+δ (Bi2212) crystal make this approach very promising. Since doping dependence of Bi2212 is an important parameter, Bi2212 crystals are annealed in vacuum or purified argon gas flow at 425 °C. For further processing we pattern both single and double rectangular mesa structures by using electron beam lithography on the cleaved surface of the crystal. Resistance-temperature (R-T), and current-voltage behavior (I-V) measurements achieved.

The authors conducted a randomized controlled trial to clarify the efficacy and safety of alendronate plus alfacalcidol versus alendronate alone in a clinical setting.Eligible patients were postmenopausal women with severe osteoporosis who were aged 70 years or older and had several risk factors for incident fractures. The primary endpoint was prevention of incident fractures, and the anti-fracture efficacy was evaluated in relation to the baseline serum 25(OH)D level.A total of 2164 patients were randomized to alendronate plus alfacalcidol (combination therapy) or alendronate alone (monotherapy). Although the overall difference in the incidence of vertebral fracture between the two groups was not significant, the combination therapy group had a significantly reduced risk of vertebral fractures after the first 6 months (HR, 0.53). In subgroup analyses, the combination therapy group was superior in the strata of number of prevalent vertebral fractures of ≥2 (HR, 0.51) and grade 3 of prevalent vertebral fractures (HR, 0.55). The rate of non-vertebral weight-bearing bone fractures was significantly lower in the combination therapy group than in the monotherapy group during the follow-up period (HR, 0.31). A lower baseline 25(OH)D level was associated with a higher incidence of non-vertebral weight-bearing bone fractures (HR, 3.42) despite alendronate use. Although one patient given the combination therapy had mild hypercalcemia, serious hypercalcemia and unknown adverse events were not encountered. Because of the limitations presented in this study, these results may not apply to female patients with longer than 2 years of treatments, and to male osteoporosis patients.The combination therapy was no more effective for overall vertebral fracture prevention. However, subgroup analysis has shown that it was more effective for fracture prevention in patients with severe vertebral deformity, multiple prevalent vertebral fractures, and for non-vertebral weight-bearing bone fracture prevention.

Fine structures were observed in the tunneling conductance of a sintered Bi 2223-SnO2 junction. The structures are weaker than those of a single crystalline Bi2212. They correspond to the Raman spectrum of Bi2223 and approximately to the phonon density of states of Bi2212. The structures must therefore be phonon structures, and phonons may contribute substantially to highTc superconductivity. Multiphonon structures are scarcely discernible. Hence we propose a new model, in place of the prior multiphonon model, to explain the rapid increase inTc with the CuO2 layer number. 2Δ (21 K)=68±4 meV inTc=98±5 K. 2Δ (0)/kBTc is 8.1±0.9. The temperature dependence of the gap was also observed and discussed.

We have developed a unique TSV structure and evaluated the connectivity between TSV and micro-bump. The connection resistances are less than 0.7 ohm and the capacitance of TSV is less than 3 pF, respectively. The electrical connection between each wafer was almost 100% and the functional yield reached more than 60%.

Good correspondence between the structure in the tunneling conductance curve and the phonon density of states shows that they are really due to phonons at least in a single phonon frequency range. The structures disappeared at T c suggesting that they are due to an exchange of phonons and not due to the inelastic tunneling. From the phonon positions, the gap parameter was found to have the BCS like temperature dependence. 2Δ(0)/ k B T c =7.1. It is isotropic in the CuO 2 plane. A conventional method to determine the gap from the conductance peak-to-peak distance is not bad.

Effects of Ta diffusion on the perpendicular magnetic anisotropy (PMA) of Ta/Co0.6Fe0.2B0.2 (12.5 Å)/MgO stacks were investigated. We found that Ta initially mixed with Co0.6Fe 0.2B0.2 and its diffusion became prominent above 300 °C. Initial diffusion of Ta into the Co0.6 Fe0.2B0.2 was not detrimental to the PMA, but a significant PMA reduction occurred when Ta migrated to the Co 0.6Fe0.2 B0.2/MgO interface. This accounts for the fact that optimizing the PMA of Ta/CoFeB/MgO requires the tuning of both CoFeB thickness and annealing temperature.

We have investigated the electronic structures of the parent compound of an iron chalcogenide superconductor TlFe2Se2 by bulk-sensitive photoemission spectroscopy (PES). Valence-band PES demonstrates the energy gap opening at the Fermi level due to the shift of Fe 3d state to the higher binding energy side as compared to the calculated density of states, being consistent with the insulating behaviour in transport measurements.

Polycrystalline NiSe, NiTe, CoSe, and CoTe have been synthesized by two methods, i.e., (1) the solid-state reaction in an evacuated quartz ampoule (QA) and (2) the high-pressure (HP) technique (HP) in a Au capsule using a cubic anvil cell. All the obtained samples have the nickel arsenide-type hexagonal crystal structure, except CoTe (HP), and their estimated lattice parameters, a and c, show almost the same values within 0.8% in comparison between samples prepared by the QA method and those by the HP method. On the other hand, a distinct difference between samples prepared by QA and HP processes is found in the magnetization of NiSe and NiTe. In particular, for NiTe, the temperature dependence of magnetization indicates two transition temperatures at about 20 and 130 K in samples prepared by the HP process. However, samples of NiTe x (x = 0.5, 0.66, 0.82, 1, 1.22, and 2) and NiTe containing Au prepared by QA process do not show similar magnetic orders in the temperature range between 2 and 300 K. Also, samples of NiSe (HP) show magnetic transition at ∼20 K, while those of NiSe (QA) show a magnetic inflection point at ∼10 K. To the best of our knowledge the remarkable difference in magnetic properties caused by the method of synthesis has not been reported. In this paper, we present comparative experimental results of magnetic, electric, and specific heat measurements of samples prepared by the two methods. A possible explanation for such a substantial difference in magnetic interaction will be discussed.

The epitaxial chemical vapor deposition of SiC on (100) and (111) Si substrates has been conducted in a cold wall furnace from methyltrichlorosilane (MTS) as the single source material. In the temperature range from 1100°C to 1350°C, both surface-reaction-limited growth and diffusion-limited growth have been observed. The activation energy for growth was decreased using a two-step process route in which an intermediate layer was deposited by controlling only the partial pressure of the MTS.

Phonon structures in the tunneling conductance must be properly normalized to evaluate the intensity of the electron-phonon interaction. However, this is very difficult because of the absence of the exact normal-state conductivity. Therefore we propose another method to judge whether or not the intensity becomes stronger with a critical temperature T c. This method compares the intensity of anharmonic structures, which are normalized to the single-phonon structures, between high- and low-T c substances. Our data for Bi-cuprates strongly suggest that the electron-phonon interaction is stronger in higher-T c substances.

A zero-bias resistance peak appeared in the tunneling resistance curve of Bi-cuprates, Na0.89WO3 and ReO3, contacted with GaAs or SnO2-x . Therefore the peak is not inherent to high-T c superconductors and may not be relevant to the electronic properties in the bulk.

A multiphonon exchange model is proposed to explain the high critical temperature and its increase with the number of CuO 2 layers between Bi(Tl) 2 O 2 layers in copper oxides. In this model, the Cooper pair is formed through the exchange of multiphonons on different CuO 2 layers.