山本 宏明

The magnetic dipole interaction between the nuclear spin of the proton and the electronic spin of the magnetic catalyst is verified for the first time. The findings of this study will open a new direction in catalyst design aided by a magnetic field.

Pt is an excellent and widely used hydrogen evolution reaction (HER) catalyst. However, it is a rare and expensive metal, and alternative catalysts are being sought to facilitate the hydrogen economy. As tungsten carbide (WC) has a Pt-like occupied density of states, it is expected to exhibit catalytic activity. However, unlike Pt, excellent catalytic activity has not yet been observed for mono WC. One of the intrinsic differences between WC and Pt is in their magnetic properties; WC is non-magnetic, whereas Pt exhibits high magnetic susceptibility. In this study, the WC lattice was doped with ferromagnetic Co nanocrystals to introduce an ordered-spin atomic configuration. The catalytic activity of the Co-doped WC was ~30% higher than that of Pt nanoparticles for the HER during the hydrolysis of ammonia borane (NH3BH3), which is currently attracting attention as a hydrogen fuel source. Measurements of the magnetisation, enthalpy of adsorption, and activation energy indicated that the synergistic effect of the WC matrix promoting hydrolytic cleavage of NH3BH3and the ferromagnetic Co crystals interacting with the nucleus spin of the protons was responsible for the enhanced catalytic activity. This study presents a new catalyst design strategy based on the concept of an internal magnetic field. The WC-Co material presented here is expected to have a wide range of applications as an HER catalyst.

The electrodeposition of Fe-Al alloy in AlCl3-NaCl-KCl-FeCl2 quaternary molten salts was investigated by potentiostatic electrolysis to prepare Fe-Al alloy film with a thermoelectric conversion function. In the AlCl3-NaCl-KCl-FeCl2 molten salts with an AlCl3/FeCl2 mole ratio of 200 (FeCl2: 32.6 mmol l(-1)), the electrodeposited Al formed a solid solution with Fe in the potential range from 0.5 to 0.2 V vs Al(III)/Al and formed the intermetallic compound of Fe3Al at the potential of 0.1 V. Fe-Al alloys containing 0.8-34.5 mol% Al were obtained by controlling the AlCl3/FeCl2 mole ratio (FeCl2 concentration) in AlCl3-NaCl-KCl-FeCl2 molten salts and the applied potential in the potential range from 0.2 to -0.1 V vs Al(III)/Al. The Fe-Al alloy films prepared in the present study exhibited the p- or n-type thermoelectric conversion, depending on their composition.

The standard Gibbs energies of formation, Delta(f)G(o), of CrB4, CrB2, Cr3B4, Cr5B3, and CrBO3 existing along the oxidation path of Cr-B binary alloy were determined using the electromotive forces of galvanic cell composed of the ZrO2-Y2O3 solid electrolyte. The electromotive force showed plateaus and decreases in the process that CrB4-CrB2 two-phase alloy used for the cell materials were oxidized via two- and three-phase regions along its oxidation path. From the plateaus of electromotive forces corresponding to the cell materials in the three-phase regions, the values of Delta(f)G(o)(CrB4), Delta(f)G(o)(CrB2), Delta(f)G(o)(Cr3B4), Delta(f)G(o)(Cr5B3), and Delta(f)G(o)(CrBO3) in the temperature range from 1273 to 1346 K were determined as follows:Delta(f)G(o)(CrB4)/J (mol of compd.)(-1) = 167500 - 261.2 T +/- 7200Delta(f)G(o)(CrB2)/J (mol of compd.)(-1) = -21020 - 79.22 T +/- 2100Delta(f)G(o)(Cr3B4)/J (mol of compd.)(-1) = -173400 - 95.47 T +/- 2500Delta(f)G(o)(Cr5B3)/compd.)(-1) = -318900 + 20.64 T +/- 5800Delta(f)G(o)(CrBO3)/J (mol of compd.)(-1) = -958800 + 59.24 T +/- 4100The Delta(f)G(o) values determined in the present study satisfied the phase equilibria in the Cr-B binary system. Using the determined Delta(f)G(o) values, the composition-oxygen partial pressure diagram of the Cr-B-O system was constructed under the conditions at 1300 K and a total pressure of 1 bar (100 kPa). It is useful to understand the oxidation property of the Cr-B binary alloys.

The standard Gibbs energies of formation, Delta(f)G degrees, of intermediate compounds of Cr3B4, CrB2, and CrB4 in the boron-rich side of the Cr-B binary system were determined by measuring electromotive forces of the galvanic cells using ZrO2-Y2O3 solid electrolyte. The phase equilibria for the Cr-B binary system were clarified to construct the cells using the solid electrolyte. The measured electromotive forces of the cells were evaluated as linear temperature functions under the conditions that the transport numbers of oxide ion in solid electrolyte were regarded as 1.0. The Delta(f)G degrees functions determined from the electromotive forces via the Nernst equation were as follows:Delta(f)G degrees(Cr3B4)/J (mol of compd)(-1) = -264540 - 26.697 T +/- 970 (1256-1322 K),Delta(f)G degrees(CrB2)/J (mol of compd)(-1) = -84572 - 32.442 T +/- 790 (1253-1350 K),Delta(f)G degrees(CrB4)/J (mol of compd)(-1) = -105120 - 57.921 T +/- 2200 (1280-1352 K).The present Delta(f)G degrees values satisfied the phase equilibria in the Cr-B binary system. Using the Delta(f)G degrees values determined in the present study, the composition-oxygen partial pressure diagram of the Cr B-O ternary system was constructed under the conditions of 1300 K and a total pressure of 1 bar (100 kPa). It is useful to understand the oxidation path of the boron-rich side of Cr-B binary alloys.

© 2019 The Japan Institute of Metals and Materials Nanoporous CeO2 was prepared implementing the dealloying method on precursors consisting of CeAl alloys characterized by different atomic arrangements. In fact, the atomic arrangement of the precursor alloy strongly influence the surface area of CeO2 in the final product. Nanoporous CeO2 with quite high surface area were formed when an amorphous CeAl alloy was used as the precursor. The catalytic performance of the catalyst that Ni was supported on CeO2 prepared from amorphous alloy were evaluated based on the reaction whereby molecular hydrogen is released from ammonia borane. A high level of catalytic activity was observed due to that fine Ni particles were dispersed on CeO2 prepared from amorphous alloy with quite high surface area.

©2018 The Japan Institute of Metals and Materials. The thermodynamic properties for Nd 2 (MoO 4 ) 3 were investigated. Nd 2 (MoO 4 ) 3 is one of the end member of the yellow phases which are known as hygroscopic harmful phases in the nuclear fuel waste glasses. The standard molar entropy, T0 S m , at 298.15 K of Nd 2 (MoO 4 ) 3 was determined by measuring its isobaric heat capacities, C p; m, from 2 K via the fitting functions including the Debye-Einstein formula and electronic- as well as magnetic terms. The Neel temperature, T N , estimated by extrapolating the magnetic-term in the fitting function. Its standard Gibbs energy of formation, f G m , was determined by combining T0 S m datum with the standard enthalpy of formation, f H m , which were estimated from ones for Ce 2 (MoO 4 ) 3 and Sm 2 (MoO 4 ) 3 . The unknown standard Gibbs energy of solution, sol G m , at 298.15 K of Nd 2 (MoO 4 ) 3 was predicted from the reference data for MoO 421 (aq) and Nd 3+ (aq). The obtained thermodynamic values are as follows: T0 S m (Nd 2 (MoO 4 ) 3 (cr), 298.15 K)/(J K 11 mol 11 ) = 439.29 « 4.39 f G m (Nd 2 (MoO 4 ) 3 (cr), 298.15 K)/(kJ mol 11 ) = 1 4072.13 « 6.14 sol G m (Nd 2 (MoO 4 ) 3 , 298.15 K)/(kJ (mol of MoO 421 (aq)) 11 ) = 73.12 « 2.33 T N /K = 1.55 « 0.16 The data obtained in the present work are expected to be useful for geochemical simulations of the diffusion of radioactive elements through underground water. [doi:10.2320/matertrans.M2018305]

© 2019 The Japan Institute of Metals and Materials. CeO2 supports were prepared via a dealloying method from amorphous alloy. The activities of Ru/CeO2 catalysts were examined in the hydrogen generation reaction from ammonia borane. To investigate the effects of atomic arrangement of CeO2 precursor on the activities of Ru/ CeO2 catalysts, CeO2 supports were prepared from amorphous alloys and crystalline alloys. The use of amorphous alloys as the precursor of CeO2 created fine porous structures, resulting in high catalytic activities of Ru/CeO2 catalysts.

© 2018 Elsevier Ltd The standard molar entropyΔ0TSm°, at 298.15 K of MgMoO4(cr) of the end-members of the yellow phases formed in the nuclear fuel waste glasses was determined by measuring Cp,m° at the temperature of 2 K and above using the most recent Debye-Einstein formula. The Δ0TSm° data obtained in our previous study for SrMoO4(cr) and BaMoO4(cr) were re-evaluated using this most recent formula. The standard Gibbs free energies of formation, ΔfGm°, of MgMoO4, SrMoO4(cr) and BaMoO4(cr) were determined by combining the Δ0TSm° data with the reference data for the standard enthalpy of formation,ΔfHm°. The ΔfGm° of MoO42−(aq) was updated from the thermodynamic cycle based on the data obtained in the present work. The unknown standard Gibbs free energy of solution, ΔslnGm°, and the solubility product, Ks, at 298.15 K for MgMoO4 were predicted. The thermodynamic values were obtained as follows: Δ0TSm°(MgMoO4(cr), 298.15 K)/(J K−1 mol−1) = 119.11 ± 1.19; Δ0TSm°(SrMoO4(cr), 298.15 K)/(J K−1 mol−1) = 136.44 ± 1.36; Δ0TSm°(BaMoO4(cr), 298.15 K)/(J K−1 mol−1) = 152.61 ± 1.53; ΔfGm°(MgMoO4(cr), 298.15 K)/(kJ mol−1) = −1295.73 ± 0.91; ΔfGm°(SrMoO4(cr), 298.15 K)/(kJ mol−1) = −1441.32 ± 1.36; ΔfGm°(BaMoO4(cr), 298.15 K)/(kJ mol−1) = −1443.29 ± 1.33; ΔfGm°(MoO42−(aq), 298.15 K)/(kJ mol−1) = −836.63 ± 0.97. ΔslnGm°(MgMoO4(aq),298.15 K)/(kJ (mol of MoO42−(aq))−1) = 3.72 ± 1.88. Ks(MgMoO4(aq), 298.15) = 2.23×10−1 ± 4.46×10−2 The thermodynamic data obtained in this work are expected to be useful for nuclear fuel waste safety management.

Abstract: The thermodynamic properties for Sm2(MoO4)3 were investigated. Sm2(MoO4)3 is the one of the yellow phase-related substances. Yellow phases are known as hygroscopic harmful phases in the nuclear fuel glasses. The standard molar entropy, Δ0TSm∘, at 298.15 K of Sm2(MoO4)3 was determined by measuring its isobaric heat capacities, Cp,m∘, from 2 K via the fitting functions including the Debye–Einstein formula and electronic as well as magnetic terms. The Néel temperature, TN, was estimated by extrapolating the magnetic term in the fitting function. Its standard Gibbs energy of formation, ΔfGm∘, was determined by combining the obtained Δ0TSm∘ datum with the reference datum of the standard enthalpy of formation,ΔfHm∘, where Δ0TSm∘ at 298.15 K of the elemental molybdenum as the standard state was re-evaluated by re-reviewing the literature. The unknown standard Gibbs energy of solution, ΔslnGm∘, and the solubility product, Ks, at 298.15 K for Sm2(MoO4)3 were predicted on the basis of the data obtained in this study and the reference datum of MoO4 2−(aq) and Sm3+(aq). The thermodynamic values determined in the present study are as follows:TN/K=1.30±0.30,Δ0TSm∘(Mo(cr),298.15K)/(JK-1mol-1)=28.573±0.086.These data are expected to be useful for geo-chemical simulation of diffusion of radioactive elements through underground water. Graphical abstract: [Figure not available: see fulltext.].

The thermodynamic properties for CaMoO4(cr), MoO3(cr) and MoO42 (aq) were investigated. CaMoO4(cr) is the one of the host crystals of the yellow phases which are known as hygroscopic harmful phases in the nuclear fuel glasses. MoO3(cr) is the main component of the host crystals. MoO42 (aq) is the aqueous ion present in underground water after dissolution of the yellow phases. The standard molar entropies, Delta S-T(0)m degrees, at 298.15 K for CaMoO4(cr) and MoO3(cr) were determined by measuring their isobaric heat capacities, C degrees(p,m), from 2 K. Their standard Gibbs energies of formation, Delta(f)G(m)degrees, were determined by combining the Delta(T)(0) S-m degrees data with the reference data of the standard enthalpies of formation, Delta H-f(m)degrees. The standard electrochemical potential, E degrees, of MoO42 (aq) was determined from the thermodynamic cycle on the basis of thermodynamic properties obtained for CaMoO4(cr) and MoO3(cr). The unknown standard Gibbs energies of solution, Delta(sln)G(m)degrees, at 298.15 K for the actinide molybdates ThMo2O8(cr) and UMoO6(cr) were predicted from the presently obtained thermodynamic data for CaMoO4(cr), MoO3(cr) and MoO42 (aq). The obtained thermodynamic values are as follows: Delta(T)(0) S-m degrees (CaMoO4(cr), 298.15 K)/(J K (1) mol (1)) = 122.23 +/- 1.22. Delta(T)(0) S-m degrees(MoO3(cr), 298.15 K)/(J K (1) mol (1)) = 75.43 +/- 0.75. Delta(T)(0) S-m degrees (MoO42 (aq), 298.15 K)/(J K (1) mol (1)) = 32.25 +/- 4.41. Delta(f)G(m)degrees (CaMoO4(cr), 298.15 K)/(kJ mol (1)) = -1437.78 +/- 1.11. Delta(f)G(m)degrees (MoO3(cr), 298.15 K)/(kJ mol (1)) = -667.20 +/- 0.63. Delta(f)G(m)degrees(MoO42 (aq), 298.15 K)/(kJ mol (1)) = -836.61 +/- 1.02. E degrees (MoO42 (aq), 298.15 K)/V = 4.34 +/- 0.01. Delta(sln)G(m)degrees (ThMo2O8(cr), 298.15 K)/(kJ mol (1)) = 184.84 +/- 42.48. Delta(sln)G(m)degrees (UMoO6(cr), 298.15 K)/(kJ mol (1)) = 68.33 +/- 34.47. The present obtained data are expected to be useful for geo-chemical simulation of diffusion of radioactive elements through underground water. (C) 2017 Elsevier Ltd.

The thermodynamic properties for the tungsten-boron binary system were determined by measuring electromotive forces of galvanic cells using an Y2O3-stabilized ZrO2 solid oxide electrolyte. Assuming that W2B and alpha WB are the stoichiometric compounds, and W2B5-x and W1-x B-3 are the nonstoichiometric compounds having solubility widths of 0.670 ae X (B) ae 0.690 and 0.805 ae X (B) ae 0.822, respectively, they were treated as the intermediate phases of W0.667B0.333, alpha W0.50B0.50, W0.330B0.670 similar to W0.310B0.690, and W0.195B0.805 similar to W0.178B0.822. The Gibbs energies of mixing, a dagger(mix) G, determined in the present study are listed as follows: Using the thermodynamic properties determined in the present study, the composition-oxygen partial pressure diagram of the tungsten-boron-oxygen system was constructed under the conditions at 1273 K (1000 A degrees C) and a total pressure of 1 bar (100 kPa). It is useful to understand the oxidation property of tungsten-boron binary alloys.

The isobaric heat capacities, C degrees(p,m), for Ag2MoO4 at 2-300 K were measured by the relaxation method. Ag2MoO4 is harmful phase formed in nuclear fuel waste glasses. The third law entropy, S degrees(m), determined via the Debye-Einstein function was: S degrees(m)(Ag2MoO4(cr), 298.15 K)/J K-1 mol(-1) = 219.87 +/- 2.20. The phase stability of Ag2MoO4 was discussed on the basis of its standard Gibbs energy of formation, Delta fG degrees(m), which was derived by combining S degrees(m) determined in this study with the reference datum of the standard enthalpy of formation, Delta fH degrees(m). Ag2MoO4 was found to exhibit greater phase stability in nuclear fuel waste glasses than transition metal molybdates such as NiMoO4 and ZrMo2O8.

The effects of addition of polyhydric alcohol such as ethylene glycol (EG) or glycerin (G) on the electrodeposition of Fe-Al alloy in AlCl3-NaCl-KCl-FeCl2 molten salts were investigated. Al content in the Fe-Al alloy electrodeposit was increased by the addition of EG or G, particularly the addition of EG was very effective. The addition of EG enable the electrodeposition of Fe-Al alloy from the molten salts with low AlCl3/FeCl2 mole ratio. From the molten salts with 4.84 mol%EG, the Al content in the electrodeposit increased with the AlCl3/FeCl2 mole ratio and Fe-Al alloy films containing 2.6 - 88.0 mol% Al were obtained. The cathodic currents derived from the reductions of Fe and Al ionic species were both decreased by the addition of EG, and it was considered that the decrease of Fe electrodeposition caused by the EG addition led the relative increase of Al content in the electrodeposit.

The preparation of cobalt-antimony thermoelectric film using pulse electrolysis was investigated in ethylene glycol (EG)-CoCl₂-SbCl₃ non-aqueous solutions at 393 K. The layered structures consisting of Co rich Co-Sb alloy layers and Sb rich Co-Sb alloy layers were obtained by applying alternately the potentials for electrodepositing the former, E_Co, and the latter, E_Sb, in the 90.0 mol%EG-9.09 mol%CoCl₂-0.91 mol%SbCl₃ bath, and were heat-treated at 673 K for 24 h in Ar gas atmosphere to prepare the Co-Sb alloy films with uniform composition. The composition of Co-Sb alloy film was found to be controlled by adjusting the ratio of applied duration at E_Co, t_Co, to one at E_Sb, t_Sb, in the potential rectangular wave used in the pulse electrolysis. At the (t_Sb / t_Co) ratio of 7.0, the Co-Sb alloy film with the composition of 26.1 mol%Co-73.9 mol%Sb was obtained after heat treatment. This alloy film was not the CoSb₃ single phase, but included it as constituent and exhibited a p-type thermoelectric conversion by the given temperature difference.

Thermoelectric materials of the Fe-Al binary system were prepared at 423 K by electrodeposition in molten salts of the AlCl₃-NaCl-KCl-FeCl₂ quaternary system. The effects of the current density at the constant content of FeCl₂ were investigated in addition to the FeCl₂ content at the constant current density on the compositions and morphologies of the electrodeposited Fe-Al alloy films. When the Fe-Al alloy films were electrodeposited in the 63.59 mol%AlCl₃-25.83 mol%NaCl-9.94 mol%KCl-0.64 mol%FeCl₂, the constant molar ratio for FeCl₂ to AlCl₃ was 1:100, the Al contents electrodeposited in the film were increased as a function of the applied current density followed by morphological change to a powder over 150 Am^－2, indicating that the current density for smooth film preparation was 100 Am^－2. At constant current density of 100 Am^－2, the various Al contents in the films were obtained as a function of the FeCl₂ content in the molten salt, resulting in the significant increase of Al content below 0.5 mol% FeCl₂ in the molten salt. Electromotive force was generated by a temperature difference on the obtained Fe-Al alloy films. The sign of generated electromotive force, the type of thermoelectric conversion, depended on the Fe-Al alloy film composition. These obtained results clarifying the condition of electrolysis to control the composition determining thermoelectric property of the film are expected to be useful to develop thermoelectric devices that use Fe-Al film.

The electrodeposition of Zn-Mg alloy was investigated in a nonaqueous solution using ethylene glycol (EG) as solvent at 393 K. ZnCl2 and MgCl2 were used as Zn and Mg ion sources and could be dissolved in EG. Zn electrodeposits containing a certain amount of Mg were obtained in EG-ZnCl2-MgCl2 baths. 8.8 mol% of Mg was coelectrodeposited with Zn in the EG-ZnCl2-MgCl2 (85.0-7.5- 7.5 mol%) bath at the cathodic current density of 300 Am-2, and Mg in this specimen was electrodeposited as Zn-Mg intermetallic compound of Mg2Zn11. The red rust occurrence time of Zn-8.8 mol% Mg alloy plated steel in 5 mass% NaCl aqueous solution at 308 K was about 16.0 times longer than that of Zn plated steel.

The WC involving the nano metal cobalt domains has been prepared by a gas-solid reaction between the cobalt nonequilibrium supersaturated-tungsten powder and carbon mono-oxide gas (CO). The metal Co domains formed in the WC were found to be spherical with a diameter of approximately 60nm by observing the microstructure with a high-resolution transmission electron microscope (HRTEM). The 88.36 mass% WC 11.64 mass% Co hard metal was prepared by liquid-phase sintering at 1623K from the powder compact which was mixture of the WC involving the Co domains and the cobalt powder as binder phase. A nano-scale fine structure composed of the WC with average diameter, dAv, of approximately 500 nm was obtained. Its Vickers hardness was found to be Hv 1663 +/- 43, being nearly equal to the 95.5mass% WC4.5 mass% Co with 12 mu m WC grains. That is, reduction of 7mass% WC was accomplished. The WC involving the Co domains is expected to be used as raw materials to form the nano-scale microstructure in the hard metals, resulting in reduction in W components.

The thermodynamic properties of the magnetic phase transition from ferro- to para-phases of AlNd2 were directly investigated by using calorimetry. The standard entropies of formation Delta S-f degrees(m,T), of the ferro- and paramagnetic phases were determined by measuring the heat capacity, C degrees(p,m), from 2 to 300 K. The standard enthalpies of formation, Delta H-f degrees(m,T), of them were determined by combining C degrees(p,m) with the standard enthalpy of formation, Delta H-f degrees(m,298), at 298 K obtained by acid solution calorimetry. The standard Gibbs energies of formation. Delta(f)G degrees(m,T), of the Ferro- and paramagnetic phases of AlNd2 were determined from their Delta S-f degrees(m,T) and Delta H-f degrees(m,T) values. The Delta(f)G degrees(m,T) values indicate that the magnetic phase transition from ferro- to paramagnetic phases occurs at 39.59 K, consistent with the observed phase transition at 39.59 K. (C) 2011 Elsevier B.V. All rights reserved.

The standard Gibbs energies of formation of Mo(2)B, alpha MoB, Mo(2)B(5), and MoB(4) in the molybdenum-boron binary system were determined by measuring electromotive forces of galvanic cells using an Y(2)O(3)-stabilized ZrO(2) solid oxide electrolyte. The results are as follows: Delta(f)G degrees (Mo(2)B)/J mol(-1) = -193100 + 44.10T +/- 700(1198 K to 1323 K(925 degrees C to 1050 degrees C)) Delta(f)G degrees (alpha MoB)/J mol(-1) = -164000 + 26.45T +/- 700(1213 K to 1328 K(940 degrees C to 1055 degrees C)) Delta(f)G degrees (Mo(2)B(5))/J mol(-1) = -622500 + 117.0T +/- 3000(1205 K to 1294 K(932 degrees C to 1021 degrees C)) Delta(f)G degrees (MoB(4))/J mol(-1) = -387300 + 93.53T +/- 3000(959 K to 1153 K(686 degrees C to 880 degrees C)) where the standard pressure is 1 bar (100 kPa).

The activities of zinc, a(Zn), and magnesium, a(Mg), from very low to high temperatures in the Mg-Zn binary system were evaluated for the first time from the relationship between the Gibbs energies of formation, Delta(f)G(T)degrees, of Mg48Zn52, Mg2Zn3, MgZn2 and Mg2Zn11 and their phase equilibria. The Delta(f)G(T)degrees values adopted were determined in our previous calorimetric studies. It was found that the a(Zn) and a(Mg) values in the compounds steeply changed from the minimum to maximum as a function of the composition in a narrow solubility range. Such a change was more emphasized toward low temperatures (3 K). Since one of the dominant factors for the composition change in a narrow solubility range in Mg48Zn52 and Mg2Zn3 is the formation of vacancies at the Zn site, the relative partial molar Gibbs energies of the vacancy formation, Delta(G) over bar (Zn vacancy)(Zn) were estimated from the obtained a(Zn) values. At 298 K, the Delta(G) over bar (Zn vacancy)(Zn) values of Mg48Zn52 and Mg2Zn3 were 73.5 and 344.3 kJ mol(-1), consistent with about the same order of the enthalpy of the vacancy formation in Ni3Al (= 173.7 kJ mol(-1)) as determined by positron annihilation spectroscopy. When the symmetric atomic configuration at the stoichiometric composition was violated by the formation of vacancies, the change in relative partial molar value of lattice defects was found to be large.

Relative partial molar Gibbs energies of the Mg component substituted into the Zn site Delta G(Mg)(-Mg on Zn site) in the intermediate phases of Mg0 4SZn0 (52) and Mg0 4Zn0 (6) in the Mg-Zn binary system were directly evaluated assuming that change in the chemical potential of magnesium Delta mu(Mg) is a function of the composition in a narrow solubility limit is caused by anti-site substitution of Mg atoms the Zn site At 298 K the Delta G(Mg)(-Mg on Zn site) values of Mg0 4Zn0 6 and Mg0 48Zn0 52 were found to be 1 254 and 0 163 MJ mol(-1), respectively consistent with about the same order of internal energy of the Fe components substituted into the Pt site Delta U-Fe(Fe on Pt site) in the ordered phase of Ll(0)-Fe1-xPt, calculated by theoretical calculation (= 0 101 MJ mol(-1)) When the symmetric atomic configuration at the stoichiometric composition was violated by anti-site substitution the relative partial molar thermodynamic value of lattice defect was found to be very large [doi 10 2320/matertrans MAW201024]

To provide for the future progression of the theoretical calculations beyond the adiabatic approximation by taking account of not only the electronic wave functions but also the nuclear wave functions, the formation energy Delta(f)E(total) determined experimentally from the ground state to the thermally excited state is inevitably necessary. In the present study, for each intermetallic compounds of the Mg-Zn and Mg-La binary systems, the standard enthalpy of formation, Delta(f)H(T)(o), which is defined as the sum of Delta(f)E(total) and the volume work, p Delta(f)V, was determined from 2 K to high temperature by combining solution calorimetry with heat capacity measurement. Because the p Delta(f)V term for solids is negligibly small, the Delta(f)E(total) values at T are approximately equal to the measured Delta(f)H(T)(o) values. Thus the Delta(f)E(total) values obtained extrapolated to 0 K from the data measured near 2 K were consistent with ones obtained by the ab initio FLAPW energetic calculation. Temperature dependences of the Delta(f)E(total) values were small below 20 K. However, the Delta(f)E(total) values over 20 K decreased linearly as a function of temperature due to the enhanced lattice vibration. In the near future, the Delta(f)E(total) values obtained in the present study will be used for constructing the nuclear wave functions in solids. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2695-2705,2009

The electrodeposition of zinc-antimony thermoelectric semiconductor film was investigated in ethylene glycol (EG) solutions containing ZnCl2 and SbCl3 or antimony potassium tartrate (APT) at 393 K. In the electrodeposition using the EG-ZnCl2-SbCl3 baths, it was difficult to control the composition of the Zn-Sb films. In contrast, Zn-Sb alloy films containing 5-96 mol% Zn were obtained in the baths using APT as the antimony ion source. The composition of the electrodeposit could be controlled easily by the current density and the concentration of the bath. Zn-Sb (55.3-44.7 mol%Sb alloy film was obtained in the EG-ZnCl2-APT (85.0-14.5-0.5 mol%) bath at lhe current density of 100 Am-2 at 393 K, and its Seebeck coefficient was 159 μV K-1. ©The Electrochemical Society.

The standard Gibbs energy of formation, Delta(f)G(T)(degrees), of MgLa in the temperature range from near absolute 0 to 525 K were determined by calorimetry. The heat capacities, C-p, from 2 K to 525 K were measured by the relaxation method and DSC. Also, a thermal anomaly at 5.9 K, which appeared to be a superconductive phase transition, was found in the obtained C-p values. The Delta(f)G(T)degrees (MgLa) values were determined by combining the C-p data with the standard enthalpy of formation at 298 K which was measured by the Calvet-type calorimeter using hydrochloric acid solution. From 2 to 300 K, the Delta(f)G(T)degrees increases gradually, and it can be evaluated as a linear function of temperature above 300 K as follows: Delta(f)G(T)degrees(MgLa) (kJ mol(-1)) = -39.236 - 6.9832 x 10(-3) T + 2.1016 x T-3 log T + 1.9114 x 10(-5) T-2 - 0.81004 T-1 +/- 7.40 (2 - 300 K), Delta(f)G(T)degrees(MgLa) (kJ mol(-1)) = -41.100 + 9.9974 x 10(-3) T +/- 7.40 (300-525 K). This result is expected to be useful as basic thermodynamic data of Mg-based alloys. (c) 2007 Elsevier B.V. All rights reserved.

The standard Gibbs energy of formation as a function of temperature of Al2Nd, Delta(f)G degrees(T)(Al2Nd), in the temperature range from near absolute 0 K to room temperature was determined by combining the measurement of heat capacities, C-p, of pure aluminium and neodymium using the relaxation method with the thermodynamic data of Al2Nd in our previous work. The temperature dependence of Delta(f)G degrees(T)(Al2Nd) was small below 10 K, and it increased monotonically above 10 K. Delta(f)G degrees(T)(Al2Nd) could be evaluated as follows: Delta(f)G degrees(T)(Al2Nd) = -104.52 - 1.8436 x 10(-2) T + 1.6273 x 10(-2) T log T -5.8437 x 10(-5) T-2 -1.5260 x 10(-2) T-1 +/- 27.3, (3-75 K) Delta(f)G degrees(T)(Al2Nd) = -104.95 + 4.4274 x 10(-3) T + 3.6408 x 10(-3) T log T -3.5175 x 10(-6) T-2 + 13.983 T-1 +/- 27.3, (75-300 K). (C) 2007 Elsevier B.V. All rights reserved.

The electronic states for the intermetallic compounds, Mg48Zn52, Mg2Zn3, MgZn2 and Mg2Zn in the Mg-Zn binary system were investigated by measuring the coefficients gamma of the electronic contribution to the heat capacities and calculating the densities of states (DOS) in the vicinities of the Fermi levels (E-F) by the DV-X alpha molecular orbital method. The gamma value of Mg2Zn was found to be nearly equal to that of pure Zn while the gamma value of Mg48Zn52 and Mg2Zn3 was similar to that of pure Mg. The gamma value of MgZn2 was comparable to the simple compositional average of the gamma values of pure Mg and Zn. Such gamma values probably result from the localization or de-localization of valence electrons, consistent with the DOS theoretically calculated by the DV-X alpha molecular orbital method. The combined use of the measured gamma and the calculated DOS is expected to provide an important method to clarify electronic states of substances as thermal spectroscopy.

Isobaric heat capacities, C-p, of LaxSr1-xFeO3-delta solid solutions from near absolute zero Kelvin (2 K) to high temperature (1340K) were measured by a relaxation method and differential scanning calorimetry. Also, their Debye temperatures, Theta(D), were determined from the measured C-p values below 10K and isochoric heat capacities, C-V, were calculated by inserting the Theta(D) values into Debye functions, followed by calculating the isochoric entropies of vibration, Delta S-T(0)V. From the measured C-p values, it was found that oxygen vacancy (V-O(center dot center dot)) formed by a self-compensating reaction by doping of Sr'(La) decreased the onset temperatures of the magnetic and structure phase transitions, broadening the temperature ranges of such phase transitions. The entropies of vibration of oxygen vacancy, Delta S-f(Tv)vib(V-O(center dot center dot)), estimated by differentiation of Delta S-T(0)V with the V-O(center dot center dot) content at 298 K and 800K were 58.65 J.K-1.mol(-1) and 64.59 J.K-1.mol(-1), respectively. Such a large Delta S-f(TV)vib.(V-O(center dot center dot)) appears to be one of important reason for foming V-O(center dot center dot).

The standard Gibbs energy of formation, AtG'T, Of M,'3La in the temperature range from near absolute zero Kelvin to 525 K were determined by calorimetry. The heat capacities, C-p, from 2 K to 525 K were measured by the relaxation method and DSC. The Delta(f)G(o)T(Mg3La) values were determined by combining the C,, data with the standard enthalpy of formation at 298 K which was measured by the Calvet-type calorimeter using hydrochloric acid solution. From 2 to 350 K, the Delta(f)G degrees(T),, increases gradually, and it can be evaluated as a linear function of temperature above 350 K as follows: Delta(f)G degrees(T)(Mg3La)/kJ mol(-1) = -76.204 - 2.5304 x 10(-2) T + 1.2160 x 10(-2) T log T + 1. 1814 x 10(-5) T-2 - 0.80332 T-1 +/- 17.0 (2-350 K) Delta(f)G degrees(T)(Mg3La)/kJ mol(-1) = -79.652 + 1.9567 x 10(-2) T +/- 17.0 (350-525 K). This result is expected to be useful as basic thermodynamic data of Mg-based alloys.

The thermodynamic properties of AINd were investigated by measuring the heat capacity, C, front near absolute zero (2 K) to 300 K using the relaxation method. During the measurement of the C-p(AINd), 4 thermal anomalies were found on the C,, Curve at 75.34, 39.79, 25.77. and 6.95 K. The third law entropy of AINd at 298 K was obtained by integrating the polynomials for the measured C,, values. The result was as follows: S-298(AINd)/J.K-1.mol(-1) = 93.72 +/- 0.47. Using this value. the standard entropy of formation at 298 K was obtained as follows: Delta S-f degrees(298)(AINd)/J.K-1.mol(-1) = -6.18 +/- 0.94.

The composition-partial oxygen pressure diagram for the Ni-B-O system at 1223 K and a total pressure of 1 bar (100 kPa) was constructed from the standard Gibbs energies of formation of the Ni-B-O system. There are eight alloys and compounds in the Ni-B-O system such as NiO in the Ni-O system, B2O3 in the B-O system, Ni3B, Ni2B, Ni0.586B0.414, Ni0.564B0.436, and NiB in the Ni-B system, and Ni3B,06 in the Ni-B-O system below 1570 K. The literature values for the standard Gibbs energies of formation of NiO and B2O3 were used for calculation, and the values for those of the others were the data obtained by measuring electromotive forces of the galvanic cell using an Y2O3-stabilized ZrO2 solid electrolyte in our previous works. The composition-partial oxygen pressure diagram constructed in this work is useful for the interpretation of high temperature oxidation property of the Ni-B binary alloy. (C) 2006 Elsevier B.V. All rights reserved.

The thermodynamic properties of Al11Nd3 were investigated by measuring the heat capacities, C-p, from near absolute zero (2 K) to 300 K by the relaxation method. In the low temperature range of 2-15 K, three lambda-type thermal anomalies were found. The third law entropy of Al11Nd3(Al0.786Nd0.214) at 298K vias obtained by the integration of polynomials for measured C-p The result was as follows: S-298(Al0.786Nd0.214) (J K(-1)mol(-1)) = -35.12 +/- 0.35. Using this value, the entropy of mixing and the standard entropy of formation at 298 K were obtained as follows: Delta S-mix(298)(Al0.786Nd0.214) (J K-1 mol(-1)) = -2.32 +/- 0.39, Delta S-f(298)degrees(Al11Nd3) (J K-1 mol(-1)) = -32.5 +/- 15.5. (c) 2006 Elsevier B.V. All rights reserved.

Anodizing of magnesium was studied in sodium metasilicate with ortho-Cresol-4-sulfonic acid aqueous solution. A gray-colored anodic oxide film was obtained in 3.0mol·dm⁻³ sodium metasilicate-0.25mol·dm⁻³ o-Cresol-4-sulfonic acid aqueous solution at constant current density of 1000A·m⁻² for 6.0×10⁵C·m⁻² at 278K. This film mainly consisted of magnesium, silicon, and oxygen and contained small amounts of carbon and sulfur. In the wear test using #800 SiC waterproof abrasive paper, this anodic oxide film showed almost the same wear resistance as that obtained in 2.0mol·dm⁻³ sodium metasilicate aqueous solution. However, in 0.86mol·dm⁻³ NaCl solution at 308K, the former without sealing showed higher corrosion resistance than the latter with sealing. Moreover, its corrosion resistance was further improved by the sealing treatment in boiling distilled water.<br>

The thermodynamic properties of Zn17Y2 and Zn12Y were investigated by calorimetry. The standard entropies of formation at 298 K, Delta S-f(298)degrees were determined from measuring the heat capacities, C-p, from near absolute zero (2 K) to 300 K by the relaxation method. The standard enthalpies of formation at 298 K, Delta H-f(298)degrees, were determined by solution calorimetry in hydrochloric acid solution. The standard Gibbs energies of formation at 298 K, Delta(f)G(298)degrees, were deter mined from these data. The results obtained are: Delta H-f(298)degrees(Zn17Y2)= -23.53 +/- 1.4kJ(.)(mol of atoms)(-1); Delta S-f(298)degrees (Zn17Y2) = -3.05 +/- 0.39 J(.)K(-1.) (mot of atoms)(-1);Delta(f)G(298)degrees (Zn17Y2) = 22.62 +/- 1.4 kJ (.) (mot of atoms) Delta H-f(298)degrees(Zn12Y) = -23.89 +/- 1.8 kJ (.) (mol of atoms)(-1) Delta S-f(298)degrees (Zn12Y) = -0.78 +/- 0.41 J (.) K-1 (mol of atoms)(-1) Delta(f)G(298)degrees, (Zn12Y) = -23.66 +/- 1.8 kJ (.) (mot of atoms)(-1). The 29 electronic contribution to the heat capacity of Zn17Y2 and Zn12Y is found to be similar to pure zinc, indicating that the valence electrons of yttrium in the compound are trapped by the density of states for zinc.

The standard Gibbs energies of formation of Ni3B, N2B, o-Ni4B3(Ni0.586B0.414), m-Ni4B3(Ni0.564B0.436), NiB, and Ni3B2O6 of the Ni-B-O system have been determined by measuring electromotive forces of galvanic cells using a Y2O3-stabilized ZrO2 solid oxide electrolyte. The results are as follows: Delta(f)G degrees (Ni3B)/J . mol(-1) = - 124,800 + 23.1 (T/K) +/- 300 Temperature range: 1198 to 1298 K Delta(f)G degrees (Ni2B)/J . mol(-1) = - 124,400 + 26.3 (T/K) +/- 300 Temperature range: 1182 to 1285 K Delta(f)G degrees (Ni0.586B0.414)/J . mol(-1) = - 47,300 + 9.70 (T/K) +/- 100 Temperature range: 1193 to 1273 K Delta(f)G degrees (Ni0.564B0.436)/J . mol(-1) = - 49,100 + 10.2 (T/K) +/- 100 Temperature range: 1193 to 1273 K Delta(f)G degrees (NiB)/J . mol(-1) = - 113,800 + 29.1 (T/K) +/- 300 Temperature range: 1203 to 1253 K Delta(f)G degrees (Ni3B206)/J . mol(-1) = - 1,934,000 + 455.5 (T/K) +/- 1000 Temperature range: 1182 to 1393 K where the standard pressure is 1 bar (100 kPa).

The preparation process of white heart malleable cast iron by heat treatment of white cast iron in Na2O-K2O-SiO2 oxide molten salts at lower temperature than usual production method was studied. The liquidus temperature of the K2O added Na2O-SiO2 (64-36 mol%) system was measured by the hot-thermocouple method and the effect of the treatment temperature on the degree of decarburization of white cast iron was investigated. The result of measuring liquidus temperature indicated that the Na2O-K2O-SiO2 (38.4-40-21.6 mol%) ternary oxide melted at about 893 K. After heat treatments of white cast iron (phi 8 mm x 8 mm) containing 3.34 mass% carbon in this oxide molten salt at 1123-1223 K for 72 h, the white heart malleable cast iron could be obtained. Although, the thickness of the surface decarburized layer decreased with the decrease of the treatment temperature, the white heart malleable cast iron having about 30 pm surface layer was obtained even at low temperature of 1123 K. The basicity of this molten salt was 2.53, which was too high to be suitable for the decarburization of white cast iron at 1323 K. It is found that white heart malleable cast iron can be prepared by the heat treatment in high basisity oxide molten salt at lower temperature than 1323 K.

The thermodynamic properties of Al2Nd were investigated by calorimetry. The standard entropy of formation of Al2Nd at 298 K, Delta S-f(298)degrees(Al2Nd), was determined from measuring the heat capacities, C-p,C- from near absolute zero (2 K) to 300 K by the relaxation method. The standard enthalpy of formation of Al2Nd at 298 K, w Delta fH(298)(0)(Al2Nd), was determined by solution calorimetry in hydrochloric acid solution. The standard Gibbs energy of formation of Al2Nd at 298 K, Delta(f)G(298)(0)(Al2Nd), was determined from these data. The results were obtained as follows: Delta S-f(298)o(Al2Nd)/J.K(-1.)mol(-1) = -10.7 +/- 1.2, Delta H-f(298)0(Al2Nd)/kJ(.)mol(-1) = -105.03 +/- 27, and Delta fG(298)(o)(Al2Nd)/kJ(.)mol(-1) = -101.85 +/- 27.

Anodizing of magnesium was studied in sodium metasilicate aqueous solutions with and without 5-sulfosalicylic acid. We investigated the experimental conditions for the formation of magnesium anodic oxide films, such as the temperature of the solution, the cell voltage during anodizing, and the concentration of the 5-sulfosalicylic acid. It was found that the anodic oxide film varied at the temperature of 338 K, and that white-colored Mg-Si-O anodic oxide films formed at lower temperatures than 338 K with high voltage in 2.0 mol·dm⁻³ sodium metasilicate aqueous solution. Addition of 0.25 mol·dm⁻³ of 5-sulfosalicylic acid to 2.0 mol·dm⁻³ sodium metasilicate aqueous solution yielded hard and gray-colored Mg-Si-O anodic oxide films containing carbon and sulfur elements. In 5 mass% NaCl solution at 308 K, the gray-colored film sealed in boiling distilled water showed higher corrosion resistance than that of the white-colored film prepared in sodium metasilicate solution.<br>