Exploratory research for new substances has been conducted in search of a phenomenon where an ion is diffused in the solid state. In addition, attempts to apply this phenomenon to secondary cells have existed for a long time, and now at last, they are about to bear fruit. This article is an overview of the history and current situation of the research, as well as how it will develop in the future, from both the point of view of academia and practical use.

Plasma diagnostics with absorption spectroscopy is a powerful tool for understanding reactions of reactive species in process plasmas because it enables us to quantitatively-measure the density of species. First, in this article, for vacuum ultraviolet absorption spectroscopy with a plasma light source, the principle for measuring the absolute density of atomic species is explained. Next, as some examples of the applications, the results of surface loss probability measurements of atomic species on several materials, real-time density monitoring of atomic species in process plasmas, and measurements of reactive species in atmospheric pressure plasma are introduced. The measurement technique for reactive species in process plasma is expected to clarify the mechanism of process plasma reactions and improve the controllability of a plasma process.

Conductive boron-doped nanodiamond (BDND) particles were prepared by deposition of a boron-doped diamond layer on a nanodiamond particle with a primary particle size of 5 nm via microwave plasma-assisted chemical vapor deposition, followed by heat treatment in air. Cyclic voltammograms in 1 M H₂SO₄ at a BDND electrode in a two-electrode system showed a large cell voltage of 1.8 V, which was much larger than that at an activated carbon (AC) electrode (0.8 V). Based on the large cell voltage, the BDND electrode showed much higher energy and power densities in 1 M H₂SO₄ than the AC electrode. Therefore, BDND should be a promising candidate for a safe and compact aqueous EDLC with high energy and power densities.

Amorphous In-Ga-Zn-O_x (a-IGZO) is expected to be a key material for the next generation of electronics. In particular, flexible devices with a-IGZO films have attracted a considerable amount of attention for next-generation flat panel displays. For low-temperature formation of a-IGZO films, an advanced plasma-assisted reactive process has been developed. In this paper, deposition of a-IGZO thin films with a plasma-assisted reactive sputter deposition system, the formation of an a-IGZO thin film transistor (IGZO TFT) using a-IGZO thin films and the fabrication of IGZO TFTs with high mobility by low temperature post-processing by plasma irradiation are reported.

From the perspective of the environmental impact, the need for a lightweight Cu substitute for wiring has been increasing to reduce CO₂ emissions and improve fuel efficiency in the fields of automobiles, aircraft and recently drones. Carbon materials, such as CNTs or graphene possess a light weight but show high electrical resistance due to the existence of crystal defect or electrical junctions. We have reported that the composite of CNTs and Cu combines light weight (40 % lighter than Cu) and high electrical conductivity comparable to Al or Au, making it a next-generation alternative to Cu. In addition, we found that the CNT-Cu composite shows higher electromigration resistance and smaller thermal expansion, suggesting the potential to improve the performance and stability of wiring materials in thermally or electrically harsh environments. In this paper, we introduce the unique performance of CNT-Cu composites, relating to their structural characteristics, and the manufacturing process by discussing the important role of uniform mixing of Cu and CNTs at the nanoscale.

The high-pressure magnetic properties of an organic radical ferromagnet including Se atoms were studied by vibrating-coil SQUID magnetometry. The magnetic state at a pressure (P) of approximately 2 GPa has the highest Curie temperature (T_C) at approximately the 30 K-level, and the analysis using mean-field theory demonstrates that an ideal three-dimensional ferromagnetic interaction network is realized there. The value of T_C observed by ac magnetic measurements is consistent with that obtained by vibrating-coil SQUID magnetometry below approximately 4 GPa. For P ＞ 6 GPa the magnetic network may be described in terms of a one-dimensional ferromagnetic chain with predominantly antiferromagnetic lateral (interchain) interactions, in accord with the results of density functional theory calculations.

Case studies on the digital transformation of field work with the dynaEdge DE100 wearable computer and the AR100 head-mounted display as an IoT device with actuation technology are introduced.