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Thermal properties of a red phosphor CaAlSiN3:Eu (CASN) at elevated temperatures were evaluated. A heat treatment at 800 °C degraded the photoluminescence property of CASN and caused irreversible changes in both the excitation and emission intensities. The heat treatment in air simultaneously decreased the N elements and increased the O elements. Consequently, the Eu2+ luminescence center was oxidized and CASN lost its photoluminescence property. Although the crystal structure of CASN host was stable even after the heat treatments, the local structure change around the Eu2+ ions is the origin of the thermal degradation of CASN. We found that the heat treatment in N2 atmosphere suppresses the thermal degradation. This is due to the suppression of N evolutions and the incorporation of O elements, which sustains the optically active Eu2+ state.

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The effect of the external magnetic field strength on the morphology of metal nickel (Ni) nanowires synthesized via electroless deposition is investigated. Under strong magnetic fields, Ni nanoparticles, precursors of Ni nanowires, easily align along the magnetic field to form straight nanowires with smooth surfaces. In contrast, under weak magnetic fields, branched Ni nanowires with rough surfaces are formed. By leveraging this magnetic effect on the morphology of Ni nanowires, simply changing the external magnetic field can synthesize various types of Ni nanowire nonwovens. Furthermore, different forms of Ni nanowires were grown on the sheet by the similar electroless deposition reaction on a non-magnetic copper metal sheet. The macroscopic morphology of this composite is closely correlated with the microstructures of Ni nanowires.

Quantitative evaluation was used to study the effect of surface roughness on wear behaviour of steel under rolling with sliding partial EHD conditions, and to clarify the effect of an additive and operating environment. It was found that the wear behaviour under conditions of lubrication with mineral oil was governed by the oxidation of the surface, regardless of whether the lubricant was formulated was with or and without additive. It was also found that wear was accelerated by the addition of fatty acid in the presence of oxygen, whereas it was not affected for lubrication with additive‐free mineral oil. It is considered that the acceleration of wear by addition of fatty acid is closely related to the oxidation of the surface during friction.