The magnetization vs. temperature curves for Ni₃Mn alloys with long range order parameters, S=0.13 and 0.29 have an inflection point near Curie point T_F. The curves show a ferromagnetic-phase profile in lower temperature and a long tail as a glass-like phase in wide temperature range above T_F. We analyzed the magnetization in the glass-like phase by using of a superferromagnetic model in which a random set of ferromagnetic clusters with intra- and inter-cluster ferromagnetic couplings is taken into account. The method which has been used for magnetic analysis of rapidly quenched La–Fe alloys by Siratori et al. is found to be adequate to analyze the magnetization in the glass-like phase for a partially ordered Ni₃Mn alloy. From these results, it is found that the magnetization in the glass-like phase depends on the average size of the ferromagnetic clusters distributed in nonmagnetic matrix. The cluster for the long range ordered Ni₃Mn contains 140–2200 atoms (1.4³–2.9³ nm³) and the volume fraction of ordered regions is 0.11–0.32, which increases with S.

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The compositional dependences of structure and magnetization for melt-spun Al–Mn–Ge alloys were examined. Metastable icosahedral(i-) and decagonal(d-) phases were found in the concentration ranges of 20 to 25 at%Mn, 0 to 20 at%Ge and 25 to 35 at%Mn, 15 to 20 at%Ge, respectively. A decagonal approximant (ap-) phase with orthorhombic (a=1.48 nm, b=1.24 nm, c=1.25 nm) structure was also formed in the range of 35 to 45 at%Mn and 15 to 30 at%Ge in as-quenched state. The ap-phase was identified as an equilibrium phase in the vicinity of 35 at%Mn and 25 at%Ge. The ap-phase appears by the peritectic reaction of liquid (L)+γ(Al₈Mn₅)→ap-phase. A large single ap-phase was synthesized by the Czochralski method and had a large magnetic anisotropy with an easy magnetization axis along the quasiperiodic direction and a hard magnetization axis along the periodic direction. By the grain size refinement of the ap- and d-phases with a large magnetization anisotropy, the intrinsic coercive force (iH_c) increased significantly. High iH_c of 504 kA/m (6.3 kOe), residual magnetization (I_r) of 15.1 μWbm/kg (12 emu/g) and magnetization of 21.4 μWbm/kg (17 emu/g) at 1430 A/m (I₁₄₃₀) were obtained for the finely mixed structure consisting of ap- and d-phases with a size of about 200 nm which was prepared by annealing the decagonal melt-spun ribbon.

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The effect of Ge addition on the microstructure and some properties was examined for rapidly solidified Si–Al–TM alloys. In particular, the addition of Ge to Si₅₅Al₂₀Fe₁₀Ni₅Cr₅Zr₅ alloy causes a change to a mixed structure in which fine Ge solid solution particles are dispersed homogeneously in an amorphous matrix. The size, volume fraction and composition of the particles depend on Ge concentration in the alloy. Fine particles, with a size less than 10 nm, were obtained in the range from 5 to 10 at% Ge. These alloys are characterized by high values of hardness (935–1085 H_V) and electrical resistivity (11.0–12.6 μΩm). Owing to the change in the matrix composition, the crystallization temperature increases with increasing Ge content and the highest value reaches 767 K. The exclusion of Ge from the amorphous phase resulted from the complicate interaction between constituent elements.

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The microstructure and texture of the aluminum strips produced by the melt direct rolling (MDR) method are inhomogeneous in the direction of strip thickness. The subsurface layer (about 30% thickness of the strips) shows fine and equiaxed grains formed by geometric dynamic recrystallization and has a strong shear texture (⟨110⟩//RD fiber texture including {111}⟨110⟩ and {001}⟨110⟩ orientations), while the center layer shows elongated grains and has a typical rolling texture. This inhomogeneity is due to large shear deformation induced by friction during rolling. Near the surface, the microstructure shows no remarkable changes during annealing below 673 K, but the relative intensities of {111}⟨110⟩ and {113}⟨110⟩ orientations increase. Relatively large \barr and very large Δr are obtained from the tensile tests of the MDR strip and they vary with the textures depending on annealing temperatures. The present study has clarified that the MDR method is useful to develop the {111} texture in aluminum strip by introduction of large shear deformation during rolling.

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Y₂O₃ and Nb₂O₅ co-doped tetragonal ZrO₂ polycrystals (TZPs) were synthesized by hot-pressing (HPing) at temperatures in the range of 1300 to 1500°C to investigate the effect of alloying on the mechanical properties of TZPs. TZPs (89.25 mol% ZrO₂-5.75 mol% Y₂O₃-5.00 mol% Nb₂O₅ and 90.24 mol% ZrO₂-5.31 mol% Y₂O₃-4.45 mol% Nb₂O₅), prepared by HPing at 1400°C for 1 h, showed a negligible monoclinic (m-) ZrO₂ content (<1%), the highest flexural strength of about 1 GPa, and the fracture toughness of above 7.5 MPa·m^1⁄2. Both low and high temperature (250 to 1000°C) aging for up to 100 h was carried out to evaluate the phase stability. TZPs, aged at temperatures higher than 400°C, suffered from strength degradation due to the extensive cavitation caused by graphite oxidation. The carbon incorporated in TZPs was identified as either an ether-type C–O or a carbonyl-type C=O. On the other hand, the specimens aged at temperatures lower than 400°C maintained the phase stability and mechanical properties.

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A previously developed method for determining elastic constants of single crystals from polycrystalline specimens was applied to cubic and tetragonal zirconia. The method is based on the orientation dependence of the lattice strain of a stressed specimen as measured by X-ray diffraction and also on Kröner’s equation relating the elastic constants of polycrystals to those of a single crystal. A simple loading device for a disc-shaped specimen was developed using a Ti–Ni shape memory alloy. The resulting elastic constants, C₁₁, C₁₂, and C₄₄ for cubic zirconia were in fair agreement with those measured directly on a single crystal. The same method was applied to tetragonal zirconia after verifying that the elasticity of this material may be well approximated by cubic symmetry. Error analysis and suggestions for an improved measurement are also included.

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The influence of the strain rate on the embrittlement of hot isostatically pressed powder metallurgy (PM) Ni₃Al alloys with boron additions has been studied at temperatures between 623–773 K. Tensile testing has been carried out in air at strain rates in the range of 10⁻⁵ to 10⁻¹ s⁻¹. The influence of powder particle size on ductility loss has also been investigated. Results indicate that high elongations to failure are achieved when the intermetallic is tested at the highest strain rate, namely 8×10⁻¹ s⁻¹ but no ductility is observed when tests are carried out within a low strain rate range. This effect is explained in terms of a reduction of oxygen-induced embrittlement when strain rate is higher than oxygen diffusion rate at the crack tip. On the other hand, the decrease in the initial particle size of the intermetallic produces the same effect on ductility as the increase in the strain rate. A microstructure of fine particles in PM Ni₃Al reduces the oxygen embrittlement.

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Crystallization of a glass with the composition of 33.9Li₂O–33.9B₂O₃–29Li₂SO₄–3.2Al₂O₃ was investigated by DTA and Dilatation methods. The electrical conductivity of the crystalline glass and the electromotive force (E.M.F.) of the concentration cell made with the crystalline glass as the solid electrolyte were measured.
The results indicate that the glass-transition temperature is 650 K and the softening temperature of the crystalline glass is higher than 971 K.
The temperature dependence of the specific conductivity are expressed as follows;
log(σ⁄(S·m⁻¹))=−5.26×10³⁄(T⁄K)+5.50 (593–833 K),
log(σ⁄(S·m⁻¹))=−1.87×10³⁄(T⁄K)+2.66 (833–971 K),
and their apparent activation energies for electrical conduction are 100.8 kJ·mol⁻¹(593–833 K) and 35.9 kJ·mol⁻¹(833–943 K).
The concentration cells showed a stable Nernstian E.M.F. corresponding to the partial pressure of SO₂ in a range of 43–800 ppm SO₂ in a stream containing 21 kPa O₂. The response time of the cell was 150 to 900 s at 873 K.

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The growth kinetics and chemical diffusion coefficients in intermetallic silicides M₅Si₃ (M=Mo and Ta ) were investigated at temperatures between 1273 and 1673 K in a vacuum capsule using Mo/MoSi₂ and Ta/TaSi₂ couples, where both disilicides were coated on Mo and Ta substrate by a CVD method. It was found that both the M₅Si₃ layers grew parabolically. Concentration profiles of Si, Mo and Ta were measured across cross-sectioned samples using an electron-probe microanalysis and chemical diffusion coefficients were obtained using Wagner’s equation on multilayer diffusion systems. Both the parabolic rate constant and chemical diffusion coefficient in the Mo₅Si₃ phase were approximately one order of magnitude larger than those of the Ta₅Si₃ phase. Activation energy for the parabolic rate constant was close to that of the chemical diffusion coefficient for each diffusion couple, showing 297 and 271 kJ/mol for the Mo₅Si₃ and Ta₅Si₃ phases, respectively. Microstructural observations indicated that Kirkendall voids formed within the Mo₅Si₃ layer close to the MoSi₂ phase, whereas there is little formation of voids in the Ta₅Si₃ layer.

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The effect of the formation of a random distribution of elements and of lattice defects in a solid during solidification processes on the thermodynamics is discussed. The relationships describing the change in melting point and the composition of the solid phase from those in the equilibrium state are derived. The effect between different species and vacancies on the interaction is discussed. The derived models are used to illustrate the effect in some aluminium and copper based alloys. The models are also used to describe the formation of divacancies and a short range ordered structure in the equilibrium state. The formation of a compounds between vacancies and alloying elements are described by the models.

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The magnetic properties of Sm–Co–Cu films and Sm–Co–Cu/Co multilayered films prepared by rf-sputtering were investigated. The addition of Cu to Sm–Co film had the effect of decrement of crystallization temperature. The Sm₂₈Co₅₉Cu₁₃ film annealed for 1 h at 623 K showed a reversible demagnetization curve with 82% springback ratio of [Mr′−M(H)]⁄[Mr−M(H)] and a high coercivity of 2480 kA·m⁻¹. This film was found to be an exchange-spring magnet film composed of the hard magnetic phase such as SmCo₅ and Sm₂Co₇ phases and a soft magnetic phase of Co. Sm₂₈Co₅₉Cu₁₃/Co(x nm) multilayered film whose Co thickness was from 0 to 15 nm was also found to be an exchange-spring magnet film.

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Manganese-tungsten oxide electrodes have high efficiency for oxygen evolution in seawater electrolysis. Manganese oxide, tungsten oxide and manganese-tungsten oxides were coated on the IrO₂-coated titanium (IrO₂/Ti electrode) by thermal decomposition. The oxygen evolution efficiencies at 200 A·m⁻² of the manganese oxide and tungsten oxide electrodes in 0.5 M NaCl solution at pH 8 and 30°C were 70 and 68%, respectively. The efficiency for oxygen evolution is enhanced by small amounts of mutual additions into manganese oxide or tungsten oxide. In particular, the efficiencies of α-Mn₂O₃-type oxide with 15 mol% W⁶⁺ and WO₃-type oxide with 10 mol% Mn²⁺ go up to over 92 and 86%, respectively. Further increase in additives leads to the formation of MnWO₄ and to a significant decrease in the oxygen evolution efficiency.

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Scanning electron microscopy and microprobe Auger electron spectroscopy were used for characterizing the morphology and the surface composition of voids in the bulk of icosahedral Al–Pd–Mn single-quasicrystals. The samples were prepared by in-situ cleavage fracture in the ultra-high vacuum. The void images could be explained on the basis of an irregular dodecahedral shape. The void facets were parallel to five-fold quasicrystal lattice planes. The surfaces of the voids grown under close-to-equilibrium conditions during the cooling of the quasicrystal were depleted in Mn and enriched in Pd with respect to the bulk.

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With the aim of evaluating a packing density of the new bulk amorphous alloys, the densities of bulk Zr₆₀Al₁₀Cu₃₀, Zr₅₅Al₁₀Cu₃₀Ni₅ and Pd₄₀Cu₃₀Ni₁₀P₂₀ alloys were measured in cast amorphous and annealing-induced crystallized states. The densities of the as-cast amorphous and crystallized phases were measured to be respectively 6.72 and 6.74 Mg/m³ for the Zr–Al–Cu alloy, 6.82 and 6.85 Mg/m³ for the Zr–Al–Cu–Ni alloy, 9.27 and 9.31 Mg/m³ for the Pd–Cu–Ni–P alloy. The annealing leading to the fully relaxed amorphous state induced slight increases of density to 6.83 Mg/m³ for the latter Zr-based alloy and to 9.28 Mg/m³ for the Pd-based alloy. The increase in density due to crystallization is evaluated to be in the range of 0.30 to 0.54% which is much smaller than that (2 to 3%) for the previously reported amorphous alloys. This result indicates that the new bulk amorphous alloys have more packed atomic configurations than ordinary amorphous alloys which require high cooling rates above 10⁴ K/s for glass formation. It is therefore thought that the higher packing density achieves the high glass-forming ability through the decrease of atomic diffusivity and the increase of viscosity. The present information obtained from the density data is consistent with the previously proposed concept for the achievement of high glass-forming ability for multicomponent amorphous alloys.

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In order to investigate morphology of spindle-type hematite (α-Fe₂O₃) particles, electron holograms were observed with imaging plates using a transmission electron microscope (TEM) equipped with a field emission gun and a biprism. Crystal thickness estimated by the shift of interference fringes agrees well with the value expected from the shape of the particle. Furthermore, local fluctuation of the interference fringes due to the particle morphology indicates the fluctuation of about 18 nm. These results clearly demonstrate that observation of holograms with new recording systems such as imaging plates is promising to characterize the detailed morphology of small particles.

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