Papers by Masao Morishita
MATERIALS TRANSACTIONS
The standard Gibbs energies of formation, ¦ f G o , of CrB 4 , CrB 2 , Cr 3 B 4 , Cr 5 B 3 , and ... more The standard Gibbs energies of formation, ¦ f G o , of CrB 4 , CrB 2 , Cr 3 B 4 , Cr 5 B 3 , and CrBO 3 existing along the oxidation path of CrB binary alloy were determined using the electromotive forces of galvanic cell composed of the ZrO 2 Y 2 O 3 solid electrolyte. The electromotive force showed plateaus and decreases in the process that CrB 4 CrB 2 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 ¦ f G o (CrB 4), ¦ f G o (CrB 2), ¦ f G o (Cr 3 B 4), ¦ f G o (Cr 5 B 3), and ¦ f G o (CrBO 3) in the temperature range from 1273 to 1346 K were determined as follows: ¦ f G o (CrB 4)/J (mol of compd.) ¹1 = 167500 ¹ 261.2 T « 7200 ¦ f G o (CrB 2)/J (mol of compd.) ¹1 = ¹21020 ¹ 79.22 T « 2100 ¦ f G o (Cr 3 B 4)/J (mol of compd.) ¹1 = ¹173400 ¹ 95.47 T « 2500 ¦ f G o (Cr 5 B 3)/J (mol of compd.) ¹1 = ¹318900 + 20.64 T « 5800 ¦ f G o (CrBO 3)/J (mol of compd.) ¹1 = ¹958800 + 59.24 T « 4100 The ¦ f G o values determined in the present study satisfied the phase equilibria in the CrB binary system. Using the determined ¦ f G o values, the composition-oxygen partial pressure diagram of the CrBO 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 CrB binary alloys.
MATERIALS TRANSACTIONS, 2021
Amorphous alloys are advantageous to obtain excellent catalytic activity from a disordered atomic... more Amorphous alloys are advantageous to obtain excellent catalytic activity from a disordered atomic arrangement and more dangling bonds. The compositional range of the NiB amorphous alloy was thermodynamically predicted. The function of the Gibbs energy of mixing, Á mix G liquid NiB , and the activities of the Ni and B components, a Niin amor: , and, a Bin amor: , of the liquid phase was extrapolated to room temperature. The negative Á mix G liquid NiB was found from X Ni = 0.45 to 0.92, indicating the existence of the liquid phase as metastable state, i.e. formation of amorphous alloy. The small a Niin amor: and a Bin amor: , that is, the strong attractive interaction between the Ni and B components suggested the liquid phase structure was stable. The NiB amorphous alloys were prepared from aqueous solution using reducing agent consistent well with the thermodynamic prediction. The preparation method from aqueous solution was useful to prevent from thermal migration of the atoms toward the equilibrium state. The quasi equilibrium oxygen pressures, p O2 (Ni in amor.), and, p O2 (B in amor.), of Ni and B components in the amorphous alloys were evaluated from a Niin amor: and a Bin amor:. p O2 (B in amor.) was found to be smaller than p O2 (Ni in amor.), revealing that B components in amorphous alloy were preferentially oxidized and inhibited Ni oxidation. Not only a characteristic disordered atomic arrangement but also chemical alloying effect of B results in the excellent catalytic activity of the NiB alloy.
MATERIALS TRANSACTIONS, 2019
CeO 2 supports were prepared via a dealloying method from amorphous alloy. The activities of Ru/C... more CeO 2 supports were prepared via a dealloying method from amorphous alloy. The activities of Ru/CeO 2 catalysts were examined in the hydrogen generation reaction from ammonia borane. To investigate the effects of atomic arrangement of CeO 2 precursor on the activities of Ru/ CeO 2 catalysts, CeO 2 supports were prepared from amorphous alloys and crystalline alloys. The use of amorphous alloys as the precursor of CeO 2 created fine porous structures, resulting in high catalytic activities of Ru/CeO 2 catalysts.
Monatshefte für Chemie - Chemical Monthly, 2018
The thermodynamic properties for Sm 2 (MoO 4) 3 were investigated. Sm 2 (MoO 4) 3 is the one of t... more The thermodynamic properties for Sm 2 (MoO 4) 3 were investigated. Sm 2 (MoO 4) 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, D T 0 S Keywords Solid states Á Lanthanoids Á Oxides Á Hydrate Á Structure-activity relationships
Journal of the Japan Society of Powder and Powder Metallurgy, 1987
Journal of the Surface Finishing Society of Japan, 2016
The preparation of cobalt-antimony thermoelectric film using pulse electrolysis was investigated ... more 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, ECo, and the latter, ESb, 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 ECo, tCo, to one at ESb, tSb, in the potential rectangular wave used in the pulse electrolysis. At the (tSb / tCo) 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.
Journal of the Japan Institute of Metals, 1990
Journal of the Surface Finishing Society of Japan, 2015
Thermoelectric materials of the Fe-Al binary system were prepared at 423 K by electrodeposition i... more Thermoelectric materials of the Fe-Al binary system were prepared at 423 K by electrodeposition in molten salts of the AlCl 3-NaCl-KCl-FeCl 2 quaternary system. The effects of the current density at the constant content of FeCl 2 were investigated in addition to the FeCl 2 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%AlCl 3-25.83 mol%NaCl-9.94 mol%KCl-0.64 mol%FeCl 2 , the constant molar ratio for FeCl 2 to AlCl 3 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 FeCl 2 content in the molten salt, resulting in the significant increase of Al content below 0.5 mol% FeCl 2 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.
MATERIALS TRANSACTIONS, 2017
The isobaric heat capacities, C • p,m , for Ag 2 MoO 4 at 2-300 K were measured by the relaxation... more The isobaric heat capacities, C • p,m , for Ag 2 MoO 4 at 2-300 K were measured by the relaxation method. Ag 2 MoO 4 is harmful phase formed in nuclear fuel waste glasses. The third law entropy, S • m , determined via the Debye-Einstein function was: S • m (Ag 2 MoO 4 (cr), 298.15 K)/ J K −1 mol −1 = 219.87 ± 2.20. The phase stability of Ag 2 MoO 4 was discussed on the basis of its standard Gibbs energy of formation, ∆ f G • m , which was derived by combining S • m determined in this study with the reference datum of the standard enthalpy of formation, ∆ f H • m. Ag 2 MoO 4 was found to exhibit greater phase stability in nuclear fuel waste glasses than transition metal molybdates such as NiMoO 4 and ZrMo 2 O 8 .
MATERIALS TRANSACTIONS, 2016
The isobaric heat capacities, C p;m , for BaMoO 4 at 2300 K were measured by the relaxation metho... more The isobaric heat capacities, C p;m , for BaMoO 4 at 2300 K were measured by the relaxation method. The third law entropy, S m , was determined via the Debye-Einstein function into which the Debye temperature, # D , as physico-chemical constant and a thermal expansion term were incorporated. # D was determined from C p;m at very low temperatures. The obtained thermodynamic properties were: S m (BaMoO 4 (cr), 298.15 K)/J K ¹1 mol ¹1 = 152.69 « 1.53; # D (BaMoO 4 (cr))/K = 295 « 3. The phase stability of BaMoO 4 was discussed on the basis of its standard Gibbs energy of formation, Á f G m. It was derived by combining S m determined in this study with the reference data of the standard enthalpy of formation, Á f H m. The thermodynamic properties obtained in the present study can be used for evaluating the hierarchy for formation of the yellow phase related-substances in nuclear waste glasses.
Pure and Applied Chemistry, 2015
Standard molar quantities of molybdate ion entropy, S m 0 , $S_{\rm{m}}^0,$ enthalpy of formation... more Standard molar quantities of molybdate ion entropy, S m 0 , $S_{\rm{m}}^0,$ enthalpy of formation, Δ f H m o , ${\Delta _{\rm{f}}}H_m^{\rm{o}},$ and Gibbs energy of formation, Δ f G m o , ${\Delta _{\rm{f}}}G_{\rm{m}}^{\rm{o}},$ are key data for the thermodynamic properties of molybdenum compounds and complexes, which are at present investigated by an OECD NEA review project. The most reliable method to determine Δ f H m o ${\Delta _{\rm{f}}}H_{\rm{m}}^{\rm{o}}$ of molybdate ion and alkali molybdates directly consists in measuring calorimetrically the enthalpy of dissolution of crystallized molybdenum trioxide and anhydrous alkali molybdates in corresponding aqueous alkali metal hydroxide solutions. Solubility equilibria of sparingly soluble alkaline earth molybdates and silver molybdate lead to trustworthy data for Δ f G m o ${\Delta _{\rm{f}}}G_{\rm{m}}^{\rm{o}}$ of molybdate ion. Thereby the Gibbs energies of the metal molybdates and the corresponding metal ions are combined with...
MATERIALS TRANSACTIONS, 2015
The heat capacities, C p;m , for SrMoO 4 at 200-300 K were measured by the relaxation method. The... more The heat capacities, C p;m , for SrMoO 4 at 200-300 K were measured by the relaxation method. The third law entropy, S m , and the Debye temperatures, # D , were determined from the measured C p;m. The obtained thermodynamic properties were: S m (SrMoO 4 (cr), 298.15 K)/ J K ¹1 mol ¹1 = 136.56 « 1.37; # D (SrMoO 4 (cr))/K = 373 « 6. Such thermodynamic properties can be used for evaluating the hierarchy for formation of the yellow phase related-substances in the nuclear waste glasses.
MATERIALS TRANSACTIONS, 2015
The catalytic performances of skeletal Cu prepared from Cu-Ti amorphous alloy heated at various t... more The catalytic performances of skeletal Cu prepared from Cu-Ti amorphous alloy heated at various temperatures were tested for the hydrogen generation from ammonia borane. The catalytic activity per surface area decreased with increasing heating temperatures of Cu-Ti amorphous alloy. The thermal treatment of Cu-Ti amorphous alloy leads to the high surface area of skeletal Cu. A skeletal Cu catalyst prepared from heated Cu-Ti amorphous alloy at 300°C which is a moderate temperature somewhat lower than crystallization temperature, exhibited a higher catalytic activity in this reaction.
The Journal of Physical Chemistry C, 2012
MATERIALS TRANSACTIONS, 2007
Isobaric heat capacities, C p , of La X Sr 1ÀX FeO 3À solid solutions from near absolute zero Kel... more Isobaric heat capacities, C p , of La X Sr 1ÀX FeO 3À solid solutions from near absolute zero Kelvin (2 K) to high temperature (1340 K) were measured by a relaxation method and differential scanning calorimetry. Also, their Debye temperatures,  D , were determined from the measured C p values below 10 K and isochoric heat capacities, C V , were calculated by inserting the  D values into Debye functions, followed by calculating the isochoric entropies of vibration, Á T 0 S V. From the measured C p values, it was found that oxygen vacancy (V O) formed by a selfcompensating reaction by doping of Sr 0 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, Á f S vib. TV (V O), estimated by differentiation of Á T 0 S V with the V O content at 298 K and 800 K were 58.65 JÁK À1 Ámol À1 and 64.59 JÁK À1 Ámol À1 , respectively. Such a large Á f S vib. TV (V O) appears to be one of important reason for foming V O .
MATERIALS TRANSACTIONS, 2007
The thermodynamic properties of AlNd were investigated by measuring the heat capacity, C p , from... more The thermodynamic properties of AlNd were investigated by measuring the heat capacity, C p , from near absolute zero (2 K) to 300 K using the relaxation method. During the measurement of the C p (AlNd), 4 thermal anomalies were found on the C p curve at 75.34, 39.79, 25.77, and 6.95 K. The third law entropy of AlNd at 298 K was obtained by integrating the polynomials for the measured C p values. The result was as follows:
MATERIALS TRANSACTIONS, 2006
The thermodynamic properties of Zn 8 La were investigated by calorimetry. The standard entropy of... more The thermodynamic properties of Zn 8 La were investigated by calorimetry. The standard entropy of formation at 298 K, Á f S 298 , was determined from measuring the heat capacities, C p , from near absolute zero (2 K) to 300 K by the relaxation method. The standard enthalpy of formation at 298 K, Á f H 298 , was determined by solution calorimetry in hydrochloric acid solution. The standard Gibbs energy of formation at 298 K, Á f G 298 , was determined from these data. The results obtained were as follows: Á f H 298 (Zn 8 La)/kJÁmol À1 = À297:18 AE 18; Á f S 298 (Zn 8 La)/JÁmol À1 ÁK À1 = À25:02 AE 3:60; Á f G 298 (Zn 8 La)/kJÁmol À1 = À289:71 AE 18. The coefficient, , of the electronic term contributing to the heat capacity of Zn 8 La was small, indicating that decrease of the density of states for 4f component of the lanthanum atom in the vicinity of E F .
MATERIALS TRANSACTIONS, 2010
Relative partial molar Gibbs energies of the Mg component substituted into the Zn site, Á " G G M... more Relative partial molar Gibbs energies of the Mg component substituted into the Zn site, Á " G G Mg on Zn site Mg , in the intermediate phases of Mg 0:48 Zn 0:52 and Mg 0:4 Zn 0:6 in the Mg-Zn binary system were directly evaluated, assuming that change in the chemical potential of magnesium, Á Mg , as a function of the composition in a narrow solubility limit is caused by anti-site substitution of Mg atoms at the Zn site. At 298 K, the Á " G G Mg on Zn site Mg values of Mg 0:4 Zn 0:6 and Mg 0:48 Zn 0:52 were found to be 1.254 and 0.163 MJÁmol À1 , respectively, consistent with about the same order of internal energy of the Fe components substituted into the Pt site, ÁU Fe on Pt site Fe , in the ordered phase of L1 0-Fe 1Àx Pt x calculated by theoretical calculation (¼ 0:101 MJÁmol À1). When the symmetric atomic configuration at the stoichiometric composition was violated by antisite substitution, the relative partial molar thermodynamic value of lattice defect was found to be very large.
MATERIALS TRANSACTIONS, 2006
The preparation process of white heart malleable cast iron by heat treatment of white cast iron i... more The preparation process of white heart malleable cast iron by heat treatment of white cast iron in Na 2 O-K 2 O-SiO 2 oxide molten salts at lower temperature than usual production method was studied. The liquidus temperature of the K 2 O added Na 2 O-SiO 2 (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 Na 2 O-K 2 O-SiO 2 (38.4-40-21.6 mol%) ternary oxide melted at about 893 K. After heat treatments of white cast iron (8 mm  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 mm 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.
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Papers by Masao Morishita