High-entropy (H-E) alloys, bulk metallic glasses (BMGs) and high-entropy BMGs (HE-BMGs) were statistically analyzed with the help of a database of ternary amorphous alloys. Thermodynamic quantities corresponding to heat of mixing and atomic size differences were calculated as a function of composition of the multicomponent alloys. Actual calculations were performed for configurational entropy (S_config.) in defining the H-E alloys and mismatch entropy (S_s) normalized with Boltzmann constant (k_B), together with mixing enthalpy (DH_mix) based on Miedema’s empirical model and Delta parameter (d) as a corresponding parameter to S_s/k_B. The comparison between DH_mix–d and DH_mix– diagrams for the ternary amorphous alloys revealed S_s/k_B ~ (d /22)². The zones S, S′ and B’s where H-E alloys with disordered solid solutions, ordered alloys and BMGs are plotted in the DH_mix–d diagram are correlated with the areas in the DH_mix – S_s /k_B diagram. The results provide mutual understandings among H-E alloys, BMGs and HE-BMGs.

Highly dispersed primary Li(Ni_1/3Co_1/3Mn_1/3)O₂ crystals, which showed high discharge capacity at a high C-rate, were grown from a Li₂MoO₄ flux.

A goal in the characterization of supported metal catalysts is to achieve particle-by-particle analysis of the charge state strongly correlated with the catalytic activity. Here, we demonstrate the direct identification of the charge state of individual platinum nanoparticles (NPs) supported on titanium dioxide using ultrahigh sensitivity and precision electron holography. Sophisticated phase-shift analysis for the part of the NPs protruding into the vacuum visualized slight potential changes around individual platinum NPs. The analysis revealed the number (only one to six electrons) and sense (positive or negative) of the charge per platinum NP. The underlying mechanism of platinum charging is explained by the work function differences between platinum and titanium dioxide (depending on the orientation relationship and lattice distortion) and by first-principles calculations in terms of the charge transfer processes.

The existence of a topological Dirac nodal loop is predicted for hydrogenated monolayer boron sheets with a nonsymmorphic symmetry. The three-center two-electron bonds in boron compounds restrict the electronic system to be insulating or semimetallic with a Dirac nodal loop. Two types of electronic structures are distinguished by the ${\mathbb{Z}}_2$ topological index and confirmed by first-principles total-energy calculations. The topological taxonomy, developed in this research, can be applied to other two-dimensional materials and to seek novel Dirac fermions.