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The hydrogen (H) loss of hydrogenated amorphous carbon (a-C:H) films, such as polymer-like, diamond-like, and graphite-like carbon films, was evaluated during elastic recoil detection analysis (ERDA) conducted using 3.4 MeV He2+. Films were formed on Si substrates via a plasma-based ion implantation and deposition method. The Raman scattering spectrometry of the films was then conducted, and except for the case of the polymer-like carbon film that had a strong photoluminescence background, two characteristic peaks corresponding to the disorder and graphite bands were observed in all cases. ERDA measurements indicated that there was no H loss in films with weak or negligible photoluminescence, whereas a decrease in H signals was clearly observed for the film with strong photoluminescence. The polymer polyphenylenesulfide (PPS: C6H4S), which is used as a standard material for ERDA measurements, showed a significant decrease in H signals under the same conditions. In comparison with the PPS, we concluded that a-C:H films with negligible photoluminescence can be used as standard materials for ERDA measurements.

Ceramics such as Li2ZrO3 and Li4SiO4 have interesting features of water vapor and carbon dioxide absorption. However, the mechanism of absorption catalysis is not well understood. The element behavior in ceramics was measured using ion beam analysis. To measure the hydrogen and other light element quantities and distribution in ceramics, in-air and time-of-flight elastic recoil detection analyses were performed. Hydrogen quantity was compared with PET film by the in-air analysis. Carbon was observed in ceramics by the time-of-flight analysis, and lithium and oxygen distributions on the surface kept in air were compared with those of ceramics stored in a vacuum.

Mn-based alloys exhibit unique properties in the spintronics materials possessing perpendicular magnetic anisotropy (PMA) beyond the Fe and Co-based alloys. It is desired to figure out the quantum physics of PMA inherent to Mn-based alloys, which have never been reported. Here, the origin of PMA in ferrimagnetic Mn$_{3-{\delta}}$Ga ordered alloys is investigated to resolve antiparallel-coupled Mn sites using x-ray magnetic circular and linear dichroism (XMCD/XMLD) and a first-principles calculation. We found that the contribution of orbital magnetic moments in PMA is small from XMCD and that the finite quadrupole-like orbital distortion through spin-flipped electron hopping is dominant from XMLD and theoretical calculations. These findings suggest that the spin-flipped orbital quadrupole formations originate from the PMA in Mn$_{3-{\delta}}$Ga and bring the paradigm shift in the researches of PMA materials using x-ray magnetic spectroscopies., Comment: 20 pages including 4 figures

An elastic recoil detection analysis (ERDA) system in air for hydrogen analysis was developed in the Wakasa Wan Energy Research Center. This system uses a thin silicon–nitride window to separate the air and vacuum regions, and the beam is irradiated through the window. Elements scattered by the beam enter the vacuum region through the same window, and are detected by an ERDA detector located there. The hydrogen sensitivity of the system was investigated by analyzing high molecular films. We used a helium beam and a stopper foil in front of the ERDA detector to ensure that only hydrogen was detected. Hydrogen energy spectra for the high molecular films and background were obtained.

A time-of-flight elastic recoil detection analysis measurement system has been developed for analyzing the light elements in thin films. The system consists of two time detectors and a silicon detector, and the energy and time-of-flight of recoil ions are measured simultaneously. This system has been tested using He, C, and Cu beams with energies between 2 and 20 MeV. Depth resolutions at the surface of a thin carbon layer were 1.3 ± 0.1 nm with a 2-MeV 4He beam and 1.6 ± 0.2 nm with a 5-MeV 63Cu beam. The sensitivity of oxygen measurements was evaluated to be 3.8 × 1014 cm−2 when using a 12-MeV 63Cu beam.

The recent discovery of hot dust grains in the vicinity of main-sequence stars has become a hot issue among the scientific community of debris disks. Hot grains must have been enormously accumulated near their sublimation zones, but it is a mystery how such a high concentration of hot grains is sustained. The most difficult conundrum is that the size of hot dust grains is estimated to lie in the submicrometer range, while submicrometer-sized grains are instantly swept away from near-stellar environments by stellar radiation pressure. One and only mechanism proposed for prolonging the residence time of hot grains in the near-stellar environments is trapping of charged nanoparticles by stellar magnetic fields. We revisit the model of magnetic grain trapping around main-sequence stars of various spectral classes by taking into account sublimation and electric charging of the grains. The model of magnetic grain trapping predicts that hot dust grains are present in the vicinity of main-sequence stars with high rotation velocities and intermediate magnetic-field strengths. On the contrary, we find that the detection of hot dust grains has no correlation with the rotation velocities of central stars nor the magnetic field strengths of the stars. Our numerical evaluation of electric grain charging indicates that the surface potential of submicrometer-sized grains in the vicinity of main-sequence stars is typically 4-5 V, which is one order of magnitude smaller than the value assumed by the model of magnetic grain trapping. On the basis of our numerical simulation on sublimation of dust grains in the vicinity of a star, it turns out that their lives end due to sublimation in a timescale much shorter than the period of one revolution at the gyroradius. It is, therefore, infeasible to dynamically extend the dwell time of hot grains inside the sublimation zone by magnetic trapping, ..., 30 pages, 8 figures, 3 tables, to appear in Planetary and Space Science

The objective of this study is to investigate the effects of neutron (n) irradiation on hydrogen isotope transport in tungsten (W). W samples were irradiated with neutrons in a fission reactor and then exposed to high flux deuterium (D) plasma at 563 K in a linear plasma device. The fraction of D release increased with increasing exposure time. In addition, the D retention in n-irradiated W increased in proportion to the square root of the plasma exposure time. These observations were explained by increase in the penetration depth of D with filling up displacement damages acting as strong trapping sites.

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2018-03-12, 資料番号: PA1810051000

Li depth profiles in Au/Si/LiPON/LCO/Au (LCO = LiCoO2, LiPON = Li3.3PO3.8N0.2) thin films battery under charging condition, prepared on self-supporting Al substrate, have been in situ measured by means of transmission elastic recoil detection (TERD) and Rutherford backscattering spectroscopy (RBS) techniques not only with 5.4 MeV He2+ ion beam without absorber, but also 9 MeV O4+ ion beam with Al absorber. In experiments with 5.4 MeV He2+, well-resolved step-wise TERD spectra have been observed, from which thickness and Li composition of constituent films of the battery are directly estimated. The Li transport from LCO to Si films through LiPON as well as return-back of Li from Si to LCO films and Li leakage into the Al substrate out of the battery system by over-charging under charging condition have been observed in the experiments both 5.4 MeV He2+ and 9 MeV O4+. The latter result indicates that these techniques are applicable to testing degradation of the battery performance by repetition of charging and discharging. Both results are compared in details with each other.

Aim To evaluate, in vitro, the mini-implant surface changes and the release of ions after immersion in artificial saliva during follow-up of 60 and 120 days. Materials and methods As for the surface features, examined in a scanning electron microscope (SEM), before and after immersion in artificial saliva, there was a rough and uneven surface, suggestive of corrosion areas for the two trademarks evaluated after 120 days of immersion. The extracts generated in artificial saliva analysis were submitted to energy dispersive spectroscopy to identify the solid corrosion products produced on the surfaces of miniscrews. Results Both SIN miniscrews and Neodent brands were observed to release minimal quantities of silver ions, chromium, iron, nickel, titanium, and vanadium. Regarding titanium, this index varied from 88.84% in the control group of Neodent brand, and 91.29% in the control group of SIN brand. For the aluminum content, the quantities ranged from 4.91% in group immersed for 60 days in Neodent brand to 8.71% for the SIN control group. Considering vanadium, the index ranged from 2.65% in the group immersed for 120 days to 4.53% in the control group, both for Neodent brand. Statistically significant differences in iron ion were observed between the control group and the miniscrews brand SIN after 60 and 120 days and for Neodent after 60 days of immersion. The titanium ions suffered statistically significant decrease for both brands after 120 days of storage when compared with the control group. Conclusion The studied miniscrews showed results consistent with the biosafety of alloys for use, in vivo. Clinical significance The knowledge of the physical/chemical state of corrosion products released in the oral cavity is very important for the toxicological assessment of metal alloys used in dental miniscrews.

Dissimilar metal joints have some advantages such as high functionality characteristics for the industrial usage. This paper describes the effect of friction welding condition on joining phenomena, tensile strength, and bend ductility of friction welded joints between Al-Mg-Si alloy (AA6063) and austenitic stainless steel (AISI 304). When joints were made at a friction pressure of 30 MPa with a friction speed of 27.5 s −1 , the upsetting (deformation) occurred at the AA6063 side. The temperature on the weld interface increased with friction time, and it reached to 623 K or over at a friction time of 1.5 s or longer. When joints were made with a friction time of 1.5 s and a forge pressure of 240 MPa, all joints had the joint efficiency of approximately 100% and the fracture in the AA6063 base metal. Furthermore, those joints had the bend ductility of 90° in a single direction with no crack at the weld interface and did not have the intermetallic compound (IMC) interlayer on the weld interface. To obtain 100% joint efficiency with good joint, the joint should be made with the following conditions: a high forge pressure such as 240 MPa, the opportune friction time that the temperature on the weld interface reached to about 623 K or higher.

Aluminium (Al) and stainless steel have such some advantages as high functionalities for the industrial usage. However, the dissimilar joints have severe problems such as generating the intermediate layer consisting of a brittle intermetallic compound (IMC interlayer) during welding process. Friction welding is very useful for making of dissimilar joint. This paper described the effect of friction welding condition on joining phenomena, tensile strength, and bend ductility of friction welded joints between pure Al (CP-Al) and austenitic stainless steel (AISI 304). The joining phenomena during the friction process such as joining behaviour, friction torque, temperature changes at the weld interface, and transitional changes of the weld interface were investigated. The effects of friction time and forge pressure on the tensile strength and bend ductility of joints were also investigated, and the metallurgical characteristics of those were observed. The joint, which had high joint efficiency, the fracture on the CP-Al side with no crack at the weld interface, and no IMC interlayer on the weld interface, could be successfully achieved. Then, the joint should be made with a high forge pressure of 150 MPa, the opportune friction time at which the temperature on the weld interface reached about 573 K or higher, and those friction welding conditions were suggested for obtaining good joints with high joint efficiency and the bend ductility of 90°.

Carbon ion cancer therapy is becoming more widespread due to its high curative effects and low burden on patients. In particle cancer therapy, it is desirable that the treatment beam irradiates the tumor from different directions in order to reduce the dose on normal cells. A rotating gantry is a suitable apparatus for meeting this requirement. Since the irradiation device orbits a patient inside the gantry, the beam can irradiate the tumor from any direction without changing the posture of the patient. Rotating gantries are already commonly used for proton cancer therapy. On the other hand, those designed for carbon ion cancer therapy have not yet been adopted because they are too large and heavy for installation in general hospitals. An R&D project to reduce the size of a rotating gantry for carbon ion cancer therapy by applying high-temperature superconducting (HTS) magnets is now in progress. It is difficult to use a coolant for the magnets mounted on the rotating gantry because they are rotating. Therefore, conduction cooling should be employed. On the other hand, the magnetic field generated by the magnets of the rotating gantry should be changed depending on the energy of the carbon ion beam in raster-scanning irradiation, and there is some possibility that the carbon ion beam will collide with the coils. This causes anomalous thermal inputs, such as those due to ac loss and beam loss, resulting in the problem of poor thermal stability of the conduction-cooled HTS coils heated by such thermal inputs. Therefore, it is important to estimate the thermal stability of the conduction-cooled HTS coils correctly. In this paper, a saddle-shaped HTS coil was designed, and the thermal runaway current of the HTS coil was numerically simulated.

Magnetic shielding is used to reduce ambient magnetic field surrounding superconducting RF cavities in order to decrease surface resistance and achieve high quality value. The tolerance of the residual magnetic field can be as low as 0.1 μT. Therefore, it is necessary to choose a proper shielding material to reduce the magnetic field to within permissible range. In this paper, field measurements are carried out using a flux gate sensor inside the magnetic shield for the superconducting RF test facility nine-cell cavity system. The measurement results at room and cryogenic temperatures are reported. A modeling method for the actual structure of the shield is developed, and the simulation results are compared with the measured results.

Because of its high curative effects and low burden on patients, carbon ion cancer therapy is becoming more widely used. The accelerated carbon ions are delivered to patients via electromagnets on a rotating gantry. One advantage of a rotating gantry is that a tumor can be irradiated with carbon ions from any direction without changing the posture of the patient. On the other hand, because of the high magnetic rigidity of carbon ions, rotating gantries for carbon cancer therapy are about three times heavier than those for proton cancer therapy, according to our estimation. Use of high-temperature superconducting (HTS) magnets has been considered for reducing the size of the rotating gantry for carbon cancer therapy. For accurate irradiation, these HTS magnets must generate high-uniformity magnetic fields, and the shape of the HTS coils was designed by 3-D analysis to generate uniform magnetic fields. In our design, saddle-shaped HTS coils were used since they can efficiently generate a magnetic field. The conductor positions and the coil end shape were optimized to generate a uniform magnetic field. On the other hand, it was difficult to maintain the HTS conductor in the designed saddle shape because it has a tapelike shape and anisotropic flexibility in bending. In this paper, the winding accuracy of the fabricated HTS saddle-shaped coil was measured, and the influence of the measurement result on the magnetic field distribution was evaluated.

This study describes experimental work examining the critical energy for direct initiation of detonation by laser ablation in a stoichiometric acetylene–oxygen mixture. The amount of input energy, the target material, and the surface roughness of the target were varied to study their effects on shock wave generation. Aluminum and stainless steel were used as target materials. The propagating shock wave induced by laser ablation was observed using high-speed shadow imaging. The critical energy for direct initiation of detonation was calculated using the strong blast wave theory. The critical input energy for aluminum was found to be lower than that for stainless steel. Because the thermodynamic critical temperature of aluminum is lower than that of stainless steel, aluminum caused a phase explosion more easily than stainless steel, thus resulting in direct initiation of detonation with a lower amount of input energy. The effects of surface roughness on critical input energy and shock wave generation were negligibly small. The critical initiation energy was estimated to be $$10.3 \pm 0.2$$ mJ, which is in agreement with the experimental data obtained in previous work. The estimated critical initiation energy was independent of the target material. However, other predictions of the critical initiation energy by using the cell size overestimated this value because of the scatter in cell size data of an unstable cellular structure. Furthermore, interaction between plasma plumes formed by laser ablation and those formed by breakdown near the target surface might have contributed to requiring a lower amount of energy for initiating detonation.

In the present study, we numerically calculated the magnetic levitation force for superconductor assisted machining (SUAM) using the finite element method. Although we usually use bulk superconductors for magnetic levitation in SUAM, we herein considered magnetic levitation using superconductor-coated conductors. We were able to explain the experimental results on the forces of the coated conductors as well as bulk theoretically. For both bulk and coated conductor, the repulsive force was found to increase as the distance from the permanent magnet became shorter. For the coated materials, both the repulsive and attractive forces were lower than in the case of bulk superconductors. This is because the volume of superconducting material was smaller than in the case of bulk superconductors, since the overall size of both materials was the same. However, we believe that greater forces can be obtained by increasing the number of coated conductors., 32nd International Symposium on Superconductivity (ISS2019), 3-5 December, 2019, Kyoto, Japan

Binary SnO−SiO2 and ternary SnO−SnF2−SiO2 glasses are investigated as potential alternative to lead containing glasses for the development of optical components using polarization light. Optical and thermal properties (including very small photoelastic constant, PEC) are reported herein. A minimum value of PEC (–0.008 × 10−12 Pa−1) is measured at a wavelength of 632.8 nm for the binary glass containing 43.6 mol% of SnO. The ternary glasses with fluorine of 8 − 9 mol% provide a very small PEC (–0.039 × 10−12 Pa−1) and blue-shifted optical absorption edge for 47.0 mol% of SnO+SnF2. The local structure of the silicate glass is investigated by micro-Raman and 119Sn, 29Si, and 19F nuclear magnetic resonance spectroscopies. It turns out that the zero PEC glass possesses a discrete silicate structure with meta- and pyro-silicate units. The relationship between the zero photoelastic property and the silicate structure is discussed.

A square shape micro-channel-plate photomultiplier tube (MCP-PMT) was developed for the Belle II TOP counter, where the count rate of the MCP-PMT is as high as several MHz/PMT due to the accelerator beam backgrounds. A major problem of the MCP-PMT in such an environment is depression of the quantum efficiency along with the integrated amount of output charge. We succeeded in diminishing the depression significantly by introducing an atomic layer deposition technique and some other processes in the production of the MCP-PMT.

The influence of the Al layer thickness on the critical current density $J_{c}$ of transformation-processed $\hbox{Nb}_{3}\hbox{Al}$ superconductors was investigated. The Al layer thickness in the jerry-roll filaments of precursor wires was varied from 120 to 250 nm; the Nb layer thickness is proportional to the Al thickness, keeping the Nb–Al composition ratio to 3. The rapid heating and quenching (RHQ) operation condition was varied within a range of the conditions to form the ductile body-centered cubic (BCC) Nb–Al phase. The RHQ wires were also followed by an areal reduction process prior to the $\hbox{Nb}_{3}\hbox{Al}$ phase transformation. Thinner Al thickness wires show a steeper increase in $J_{c}$ with reduction in the area, whereas thicker Al thickness wires show a slower increase. The best $J_{c}$ performance was obtained for the thinnest Al thickness sample. Without areal reduction, there was not much difference in the optimum $J_{c}$ with respect to the Al thickness.

Two kinds of joints (the lap and butt joints) for JT-60SA poloidal field coil are evaluated. We measured and analyzed AC losses of the joints for JT-60SA under a time-varying magnetic field, and based on the analytical AC loss, the temperature rise of the joints is estimated at the plasma disruption by using the FEM simulation software COMSOL Multiphysics. As a result, the maximum temperature of the lap joint is constant, on the other hand, the maximum temperature of the butt joint strongly depends on the mass flow of the supercritical helium. When the mass flow of the supercritical helium is 4 g/s and more in all the initial temperatures (4.2-7.0 K), the butt joint has a sufficient temperature margin at the plasma disruption. The obtained results become fundamental data to estimate the temperature margin of the coil.

Intentionally carbon (C) doped (0 0 0 1)GaN was grown using C2H2 on a sapphire substrate by metalorganic vapor phase epitaxy. Optical spectra of the heavily doped samples were investigated at room temperature. In Raman spectra excited by the 325 nm line of a He–Cd laser, multiple LO phonon scattering signals up to 7th order were observed, and the A1(LO) phonon energy was determined to be 737.5 cm−1 (91.45 meV). In infrared reflectance spectra, on the other hand, a local vibration mode was found at 777.5 cm−1, which is attributed to a Ga–C bond in the GaN matrix suggesting that the C sits on an N site (CN). In spite of the strong suggestion of CN, the samples did not show p-type conduction. Possible origin of the carrier compensation is discussed in relation to the enhancement of defect related yellow luminescence in the photoluminescence spectra.

It is necessary to develop a measurement technology of planar magnetic cores at higher frequencies and higher power ranges to develop better power supply on chip (PwrSoc).

L1 0 -MnGa alloy film is thermodynamically stable and shows a large perpendicular magnetic anisotropy (PMA), small saturation magnetization, and small damping constant.

Perpendicularly magnetized ultrathin films of magnetic metals are technologically important for various spintronic applications, such as the free layer in magnetic tunnel junctions (MTJs) for the spin-transfer-torque (STT) magnetoresisive random access memory (MRAM) and in current-perpendicular magnetoresisive devices for the spin-torque radio frequency (rf) oscillators and detectors.

Phase formation involving icosahedral quasicrystals (iQc) in the Mg–Cd–Yb system was investigated. The phase diagrams obtained revealed that the iQc is in equilibrium with either (Mg, Cd)2Yb or an α-Mg phase over a wide composition range at 673 K. A eutectic reaction, where the melt decomposed to a rod-like lamella structure consisting of iQc and α-Mg phases was observed for Mg68Cd24Yb8 at 735 K. High-angle annular dark-field scanning transmission microscopy observation of the iQc in Mg96Cd3Yb1 verified the atomic positions of the Yb icosahedra and confirmed that the i-MgCdYb is isostructural to the i-CdYb. The formation of the eutectic structure is responsible for the high stability of the iQc/α-Mg interfaces because of good lattice matching; which is coincident interplanar spacing over several planes for the two phases. This coincidence in interplanar spacing was further confirmed in the real atomic structure, for which the twofold planes of the iQc, and the [0 0 0 2] and [2 −1 −1 0] planes of α-Mg are dominant factors in determining the stability of the interfaces.

(Nd 0.1 Eu 0.1 Gd 0.8 )Ba 2 Cu 3 O y “NEG-123”superconductors were synthesized as a function of BaO 2 content with the aim of reducing NEG/Ba substitution and preparing batch production in air. The DTA data were used to schedule the heat treatment profile of the melt growth process. The magnetization measurements indicated that superconducting transition temperature increased with increasing the BaO 2 concentration and a T c (onset) reached around 95 K for the sample with 24 mol% BaO 2 , which is similar to the NEG samples processed in reduced oxygen pressure. Moreover, the superconducting transition temperature decreased when BaO 2 content exceeded 28 mol%. The irreversibility field was increased with increasing the BaO 2 concentration and reached >5 T for the sample with 24 mol% BaO 2 and decreased thereafter. The experimental results suggest that the present approach will contribute to large scale batch production of melt-processed NEG-123 materials in air.

A variable gain erbium-doped fiber amplifier (EDFA) with a wide gain range and a small noise figure (NF) variation is analyzed numerically and demonstrated experimentally. The EDFA can change the total erbium-doped fiber length by selecting six combinations of three EDFs with optical switches (SWs). The numerical calculation of the NF and the pump power using the analytical model of an EDFA indicates that such a variable gain EDFA has an advantage over a conventional multi-stage EDFA in terms of NF variation and required pump power. These characteristics are demonstrated by constructing a variable gain EDFA that employs SWs and variable optical attenuators (VOAs) integrated on a silica-based planar lightwave circuit (PLC). The variable gain EDFA exhibits a smaller NF variation of 1.2 dB for the 24-dB variable gain range than conventional two- and four-stage EDFAs, which have NF variations of 12.6 and 2.0 dB, respectively, for the same variable gain range. The power consumption of these EDFAs is also discussed by comparing the operating electric power of the SWs and VOAs with that of the pump laser.

In this paper, the authors have proposed a possibility of a magnetic field biasing tunable inductive device. To confirm a new scheme, a tunable coplanar waveguide (CPW) resonator with a combination of soft magnetic thin film and hard magnetic film has been fabricated and evaluated. The magnetic pole of hard magnetic film can be controlled by magnetization using a pulsed magnetic field. A bias magnetic field is applied in the soft magnetic film from the magnetic pole of the hard magnet film. Consequently, permeability of the soft magnetic film can be controlled by changing amplitude of the pulsed magnetic field in the magnetizing for the hard magnetic film. A 20 mm long coplanar wave guide resonator has been fabricated using FeSiO/SiO2 granular multilayer film and FeCoSm amorphous hard magnetic film. From the experimental results, in case of using 0.2 mu m thick soft granular film, by changing amplitude of the 1 ms width current-pulse for magnetizing pulsed magnetic field for hard magnetic film, the maximum inductance change was up to 18%, and maximum change of the resonant frequency was 9.6%. The control energy for one time tuning was small enough (5.4 mu Wh)., Article, IEEE TRANSACTIONS ON MAGNETICS. 49(3):978-981 (2013)

(Nd, Eu, Gd)-Ba-Cu-O ternary bulk superconductors have high potential for practical applications since they exhibit very high critical current densities and thus high field trapping capabilities. (Nd, Eu, Gd)-Ba-Cu-O superconductors are synthesized in a reduced oxygen atmosphere, which requires a control of oxygen partial pressure and needs a special device for hot seeding. In the present study, for simplicity, we employed Ar gas flow into the furnace to control oxygen partial pressure instead of flowing oxygen-controlled gas. Hence, it was necessary to modify the melt processing conditions to produce a single domain. Through the optimization of seeding temperature and cooling rate, we obtained the processing conditions, in which a single domain bulk (Nd, Eu, Gd)-Ba-Cu-O of 20 mm diameter could be synthesized.

An effective way to improve the superconducting properties in REBa 2 Cu 3 O y (REBCO) films under a magnetic field is to dope artificial pinning centers (APC). The pinning performance depends on the content of the APC materials. Usually, the optimal APC content is explored by preparing films one at a time from the REBCO target using different APC material content, which is an extremely time-consuming process. The combinatorial-PLD (C-PLD) method allowed us to prepare films that continuously changed in composition across a single substrate. In this study, we used the C-PLD method to prepare BaSnO 3 (BSO)-doped YBCO films. The films were deposited on SrTiO 3 substrate using a fourth-harmonic Nd:YAG laser. From the results of the J c – B curves at 77 K and B // c , the film that contained 3.2 vol.% of BSO exhibited the best pinning performance in this study. We showed that the C-PLD method was efficient for quick screening of the optimal APC content with only one deposition. We also used the C-PLD method to explore new APC materials, and proved that it can quickly evaluate the new APC materials Ba 3 Cu 3 In 4 O 12 and BaTbO 3 .

Immediately after the GeV-implantation of 57Mn nuclei produced by the RIKEN-RIBF facility, 57Mn/57Fe Mossbauer spectra in Si-solar cells are measured under light illumination. Comparing with the spectrum of p-type multi-crystalline-Si, the broad spectra of the solar cell under operation can be analyzed as a superposition of interstitial and substitutional Fe components with different charge states. The charge states of Fe impurities are created by the excess carrier injection followed by a directional carrier flow in the p-n junction. The present results provide us a possibility to clarify the carrier trapping process at the Fe impurities in Si-solar cells.

The forward and reverse current density–voltage ( J – V ) and capacitance–voltage ( C – V ) characteristics of pentacene/n − -silicon heterojunction diodes were investigated to clarify the carrier conduction mechanism at the organic/inorganic heterojunction. Current rectification characteristics of the pentacene/n − -Si junctions can be explained by a Schottky diode model with an interfacial layer. The diode parameters such as Schottky barrier height and ideality factor were estimated to be 0.79–1.0 eV and 2.4–2.7, respectively. The C – V analysis suggests that the depletion layer appears selectively in the n − -Si layer with a thickness of 1.47 μm from the junction with zero bias and the diffusion potential was estimated at 0.30 eV at the open-circuit condition. The present heterojunction allows the photovoltaic operation with power conversion efficiencies up to 0.044% with a simulated solar light exposure of 100 mW/cm 2 .

Pulsed-field magnetization (PFM) is one of the practical activation techniques for bulk applications, especially as an inexpensive, small-volume, and mobile experimental setup. To utilize the method, its effectiveness to excite the bulk superconductors was examined by four samples with different trapped-flux performance as representatives. The PFM experiments were conducted with a pair of vortex-type copper coils at liquid nitrogen temperature (77 K). The utmost trapped-flux performance of the four samples was obtained by a multi-PFM method with progressively increased applied fields. By comparison with their trapped-flux results of static field-cooling magnetization (FCM), the effectiveness of PFM according to different performance bulk superconductors was analyzed. It was found that with the improvement of the bulk performance, the PFM results start to deviate from the FCM ones more and more, indicating a harder tendency to excite the bulk samples by the PFM method. The possible explanations from heat generation during the pulse and some suggestions to the improvement of the PFM process for practical applications are discussed.