The substitution of aluminum with scandium in the mixed yttrium aluminum scandium garnets, Y 3 Sc x Al 5--x O 12 (x ¼ 0, 0.05, 0.5, 1.5), was studied for the first time using 27 Al magic angle spinning (MAS), multiple quantum (MQ) MAS NMR, and 45 Sc MAS NMR. The aluminum and scandium quadrupole coupling constants and isotropic chemical shifts were evaluated for all garnets under study. 27 Al 2D spectra evidenced variation of the isotropic shifts over the aluminum sites in the mixed garnets.

Results of NMR studies of 23 Na in NaNO 2 confined within molecular sieves MCM-41 with pore size 37 and 20Å and SBA-15 with pore size 52Å are presented. 23 Na spin-lattice relaxation and line shape were measured in a large temperature range up to 535 K covering the bulk ferroelectric phase transition point. It is shown that confined NaNO 2 below the bulk sodium nitrite melting point consists of two parts with relaxation times which differ by two orders in magnitude. A portion of NaNO 2 exhibits bulk-like properties with the ferroelectric phase transition in the vicinity of the bulk transition temperature. The bulk-like NaNO 2 prevails below and near the ferroelectric phase transition and its amount decreases strongly when temperature approaches the bulk melting point. Fast nuclear relaxation in another portion of confined NaNO 2 revealed very high molecular mobility. This portion increases with increasing temperature and dominates above 510 K. It was suggested that fast relaxation corresponds to the melted or premelted state of confined NaNO 2 caused by confinement. Temperature evolution of the 23 Na NMR line confirms such a suggestion. The amount of NaNO 2 which possesses high molecular mobility depends on pore size and is maximal for the MCM-41 porous matrix with 20Å pore size. The correlation time of electric field gradient fluctuations was found for this part to be similar to those in viscous liquids with the activation energy of about 0.42 eV.

Ultra-wide bandgap beta-gallium oxide (β-Ga2O3) has been attracting considerable attention as a promising semiconductor material for next-generation power electronics. It possesses excellent material properties such as a wide bandgap of 4.6–4.9 eV, a high breakdown electric field of 8 MV/cm, and exceptional Baliga’s figure of merit (BFOM), along with superior chemical and thermal stability. These features suggest its great potential for future applications in power and optoelectronic devices. However, the critical issue of contacts between metal and Ga2O3 limits the performance of β-Ga2O3 devices. In this work, we have reviewed the advances on contacts of β-Ga2O3 MOSFETs. For improving contact properties, four main approaches are summarized and analyzed in details, including pre-treatment, post-treatment, multilayer metal electrode, and introducing an interlayer. By comparison, the latter two methods are being studied intensively and more favorable than the pre-treatment which would inevitably generate uncontrollable damages. Finally, conclusions and future perspectives for improving Ohmic contacts further are presented.

A measurement of the production of a prompt J/ψ meson in association with a W ± boson with W ± → µν and J/ψ → µ + µ − is presented for J/ψ transverse momenta in the range 8.5-150 GeV and rapidity |y J/ψ | < 2.1 using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of √ s = 8 TeV and correspond to an integrated luminosity of 20.3 fb −1. The ratio of the prompt J/ψ plus W ± cross-section to the inclusive W ± cross-section is presented as a differential measurement as a function of J/ψ transverse momenta and compared with theoretical predictions using different double-parton-scattering cross-sections.