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In this study we prepared Y x Yb1-x Ba2Cu3O7-δ (x = 0.1, 0.2, 0.3, 0.4, 0.5) powders and bulks to use as intermedium for superconducting joint between REBCO-coated conductors. Superconducting joints are essential in the development of high-field REBCO persistent magnets. All the powders and bulks were sintered at 850 °C for 10 hours in air. Bulks were prepared by pressing at 70 MPa. Calcination of the bulks was performed under the same conditions as the powders. Two joint samples between GdBa2Cu3O7-δ -coated conductors were prepared by using the bulk samples. For x=0.1, a superconducting joint was successfully obtained.

We previously discovered a novel pathway for the transformation from highly orientated pyrolytic graphite foils irradiated with neutrons into amorphous diamond platelets. Here, we utilized graphite foils irradiated with a neutron dose of about a half of the previous study, and confirmed the pathway for the transformation. Raman spectrum of the irradiated graphite exhibits a broad amorphous one but still possessed weak G and D peaks, appearing in a less disordered state. The irradiated graphite foils were shock compressed at 46, 51 and 54 GPa. At 46 GPa, Raman spectra clearly show the G and D peaks but a weak photoluminescence appears. At 51 GPa, we can find transparent platelets with intense photoluminescence but no diamond Raman peak, implying the transformation to amorphous diamond. At 54 GPa, we obtained transparent platelets with intense photoluminescence and a small and broad diamond peak, suggesting the formation of nano-diamond.

24th IUPAP Conference on Computational Physics (IUPAP-CCP 2012), To check the validity of the recently proposed kinetic energy (KE) functional of the pair density (PD) functional theory, we perform the numerical calculation for the neutral Ne atom. This is the first computational trial for the PD functional theory which includes the KE functional that is approximately derived on the basis of the rigorous expression with the coupling-constant integration. In this work we adopt the correlated Thomas-Fermi functional as the approximate KE functional. Although it is shown that non-negligible errors exist in the resulting PD, the present results will be useful as reference data in cases of developing further the approximate KE functional., Article, Journal of Physics: Conference Series. 454:012056 (2013)