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We have observed zero resistivity above 10 K and an onset of resistivity reduction at 25.2 K in a heavily B-doped diamond film. However, the effective carrier concentration is similar to that of superconducting diamond with a lower Tc. We found that the carrier has a longer mean free path and lifetime than in the previous report, indicating that this highest Tc diamond has better crystallinity compared to that of other superconducting diamond films. In addition, the susceptibility shows a small transition above 20 K in the high quality diamond, suggesting a signature of superconductivity above 20 K. These results strongly suggest that heavier carrier doped defect-free crystalline diamond could give rise to high Tc diamond. [ABSTRACT FROM AUTHOR]

We have performed a photoemission spectroscopy (PES) study of CeM2Al10 (M = Fe, Ru, and Os) to directly observe the electronic structure involved in the unusual magnetic ordering. Soft X-ray resonant (SXR) PES provides spectroscopic evidence of the hybridization between conduction and Ce 4/electrons (c-f hybridization) and the order of the hybridization strength (Ru < Os < Fe). High-resolution (HR) PES of CeRu2Al10 and CeOs2Al10, as compared with that of CeFe2Al10, identifies two structures that can be ascribed to structures induced by the c-f hybridization and the antiferromagnetic ordering, respectively. Although the c-f hybridization-induced structure is a depletion of the spectral intensity (pseudogap) around the Fermi level (EF) with an energy scale of 20-30 meV, the structure related to the antiferromagnetic ordering is observed as a shoulder at approximately 10-11 meV within the pseudogap. The energies of the shoulder structures of CeR2Al10 and CeOs2Al10 are approximately half of the optical gap (20meV), indicating that EF is located at the midpoint of the gap. [ABSTRACT FROM AUTHOR]

Unconventional Cooper pairing originating from spin or orbital fluctuations has been proposed for iron-based superconductors. Such pairing may be enhanced by quasi-nesting of two-dimensional electron and hole-like Fermi surfaces (FS), which is considered an important ingredient for superconductivity at high critical temperatures (high-Tc). However, the dimensionality of the FS varies for hole and electron-doped systems, so the precise importance of this feature for high-Tc materials remains unclear. Here we demonstrate a phase of electron-doped CaFe2As2 (La and P co-doped CaFe2As2) withTc=45 K, which is the highest Tc found for the AEFe2As2 bulk superconductors (122-type; AE = Alkaline Earth), possesses only cylindrical hole- and electron-like FSs. This result indicates that FS topology consisting only of two-dimensional sheets is characteristic of both hole- and electron-doped 122-type high-Tc superconductors. [ABSTRACT FROM AUTHOR]

We use core level and valence band soft X-ray photoemission spectroscopy (SXPES) to investigate the electronic structure of new BiS2 layered superconductor LaO1-xFxBiS2. The core level spectra of doped samples show a new spectral feature on the lower binding energy side of the Bi 4f main peak, which may be explained by core-hole screening with metallic states near the Fermi level (EF). The experimental electronic structure and its x dependence (a higher binding energy shift of the valence band as well as appearance of new states near EF having the dominant Bi 6p character) were found to be consistent with the predictions of band structure calculations in general. Noticeable deviation of the spectral shape of the states near EF from that of calculations might provide insight into interesting physical properties. This study provides the first experimental electronic structure of the new BiS2 layered superconductors. [ABSTRACT FROM AUTHOR]

Background: The use of laparoscopy is increasing in various surgical disciplines, including living donor kidney transplant (LDKT). In laparoscopic transplants, vessel length of the donor kidneys often falls short. This makes anastomosis to the recipient's external iliac vein difficult, which may cause problems when blood circulation reconstruction is required. Renal vein elongation (RVE) is often needed, but the available materials may fall short in terms of post-transplant vessel function. Objective and methods: We aimed to determine whether the gonadal vein was a viable option for RVE in LDKT. We therefore performed LDKT in three cases wherein RVE was performed using the gonadal vein. We used the cylindrical method wherein the donor's gonadal vein was shaped into a cylinder, and the vessel was extended end-to-end with the renal vein. Results: All cases showed immediate graft function after surgery. The total ischemic time was 151, 168, and 169 min in cases 1, 2, and 3, respectively. The serum creatinine levels at discharge were 0.98 mg/dL, 2.07 mg/dL, and 1.16 mg/dL in cases 1, 2, and 3, respectively. None of the patients developed any complications during their hospital stay. Conclusion: Since the renal vein was extended using a gonadal vein, vessel suturing with the external iliac vein became easier; as a result, bleeding and outflow block could be prevented.

Synchrotron-based angle-resolved photoemission spectroscopy is used to determine the electronic structure of layered SnSe, which was recently turned out to be a potential thermoelectric material. We observe that the top of the valence band consists of two nearly independent hole bands, whose tops differ by ∼20 meV in energy, indicating the necessity of a multivalley model to describe the thermoelectric properties. The estimated effective masses are anisotropic, with in-plane values of 0.16–0.39 m0 and an out-of-plane value of 0.71 m0, where m0 is the rest electron mass. Information of the electronic structure is essential to further enhance the thermoelectric performance of hole-doped SnSe. [ABSTRACT FROM AUTHOR]

We studied the electronic structure of Ca10(Pt4As8)(Fe2-xPtxAs2)5 for two platinum concentrations with different Tc using ARPES. From the carrier number estimated from the areas of FS sheets, we found that the Pt substitution induces electron doping into the Fe2As2 layers (effectively two electrons per Pt atom). In addition, we found that the FS nesting condition in x = 0.25 is stronger than that in x = 0.42, indicating close correlation between the FS nesting and Tc. [ABSTRACT FROM AUTHOR]

The electronic structure of nearly optimally doped novel superconductor LaO1-xFxBiS2(x= 0.46) was investigated using angle-resolved photoemission spectroscopy (ARPES). We clearly observed band dispersions from 2 to 6 eV binding energy and near the Fermi level (EF), which are well reproduced by first-principles calculations when the spin-orbit coupling is taken into account. The ARPES intensity map near EF shows a squarelike distribution around the Γ(Z) point in addition to electronlike Fermi-surface (FS) sheets around the X(R) point, indicating that FS of LaO0.54F0.46BiS2 is in close proximity to the theoretically predicted topological change. [ABSTRACT FROM AUTHOR]

We report the results of photoemission spectroscopy on the potassium concentration (x) dependence of Kx picene films on graphite. The results show a systematic shift of a whole valence band and the appearance of a clear Fermi edge for a certain value of x, with additional structures at higher binding energies. Observed spectral evolutions are reminiscent to those of doped C60, implying that the Kx picene film has multiple phases depending on the K concentration. Appearance of a clear Fermi edge, in contrast to multilayer Kx picene films on Au, SiO2, and Ag(111) substrates, where no clear Fermi edges are observed, suggests that the emergence of the metallic states for Kx picene films depends on the specific molecular orientations in the films on different substrates. [ABSTRACT FROM AUTHOR]

Using high-resolution spin-resolved photoemission spectroscopy, we observe a thermal spin depolarization to which all spin-polarized electrons contribute. Furthermore, we observe a distinct minority spin state near the Fermi level and a corresponding depolarization that seldom contributes to demagnetization. The origin of this depolarization has been identified as the many-body effect characteristic of half-metallic ferromagnets. Our investigation opens an experimental field of itinerant ferromagnetic physics focusing on phenomena with sub-meV energy scale. [ABSTRACT FROM AUTHOR]

We use soft x-ray photoemission spectroscopy (SXPES) to investigate Ce 4f electronic states of a new BiS2 layered superconductor CeO1-xFxBiS2, for polycrystalline and single-crystal samples. The Ce 3d spectrum of the single crystal of nominal composition x=0.7 has no f0 component and the spectral shape closely resembles the ones observed for Ce trivalent insulating compounds, strongly implying that the CeO layer is still in an insulating state even after the F doping. The Ce 3d-4f resonant SXPES for both polycrystalline and single-crystal samples shows that the prominent peak is located around 1 eV below the Fermi level (EF) with negligible spectral intensity at EF. The F-concentration dependence of the valence band spectra for single crystals shows the increases of the degeneracy in energy levels and of the interaction between Ce 4f and S 3p states. These results give insight into the nature of the CeO1-xFx layer and the microscopic coexistence of magnetism and superconductivity in CeO1-xFxBiS2. [ABSTRACT FROM AUTHOR]

We have made 53Cr NMR measurements on polycrystalline and single-crystalline film samples to study the local electronic state of a half-metallic ferromagnet CrO2 which has the rutile structure with one crystallographically equivalent Cr site. We observe two kinds of 53Cr NMR spectra in the ferromagnetic state of both the samples. An analysis on the hyperfine field shows the presence of two Cr sites with different orbital occupancies, suggesting that a local orbital order takes place with breaking the local symmetry in the rutile structure. This may be ascribed to the negative charge transfer between chromium and oxygen ions. [ABSTRACT FROM AUTHOR]