S Takeda

Thermodynamic properties of liquid Na-Cd and Na-In

New measurements of the free energy and entropy of mixing and the associated thermodynamic properties of liquid Na-Cd and Na-In alloys are reported. It is inferred that there exists some kind of short-range order of Na, whilst there is a phase separation tendency in the alloys in the Na-rich region. These contradictory features are interpreted in terms of the interchange energies in the alloys which vary as a function of Na concentration.

A compound-forming effect in liquid Hg-Na alloys

The thermodynamic data of liquid Hg-Na alloys have been analysed in terms of the idea of compound formation. However, little deviations from a linearly interpolated curve are observed in the magnetic susceptibility of those alloys, suggesting that the electronic structures are not changed by the compound formation. The anomalous behaviour of the electrical resistivity of these liquid alloys is also interpreted in terms of the Faber-Ziman formula.

EMF measurements on liquid Na-Hg alloys and their thermodynamic properties

The EMF of the liquid Na-Hg system has been measured as a function of temperature and from these measurements we have obtained the thermodynamic quantities of mixing: Delta G, Delta S and Delta H. The temperature variations of Delta H were observed. The authors then estimated Delta Cp, the additional specific heat by alloying. In connection with this, the fluctuations in the long-wavelength limit Scc(0), SNN(0), SNc(0) and the partial structure factors aij(0) of Faber-Ziman type were estimated. They also estimated the local ordering parameter from these partial structure factors.

Compound-forming effect for the electronic properties of liquid Sn-Te alloys

The electrical resistivity of liquid Sn-Te alloys has been measured as a function of temperature and concentration. The resistivity isotherm has a remarkable maximum around the equiatomic composition, suggesting that a kind of compound formation exists at this composition. The compound fraction is estimated as a function of concentration using thermodynamic analysis. The electrical resistivities and the magnetic susceptibilities are interpreted consistently in terms of the compound formation of SnTe.

Magnetic susceptibilities of liquid K-Sn alloys

The magnetic susceptibility of liquid K-Sn alloys has been measured as a function of temperature and concentration. The curve of the susceptibility isotherm exhibits a distinct minimum around the composition K0.55Sn0.45. This anomaly in the concentration dependence of the electronic behaviour is discussed in terms of compound formation.

Thermodynamic aspects of charge transfer in liquid alloys

Charge transfers in liquid Cs-Na, Na-Pb and Na-Sn alloys are estimated using partial structure factors in the long-wavelength limit and Thomas-Fermi screening theory. It is verified that the results are consistent with the magnetic susceptibility data for liquid Na-Pb and Na-Sn previously measured by the present authors.

Compound-forming effect for the electrical resistivity of liquid IVB-Te alloys

Abstract The resistivity isotherm of liquid IVb(Sn,Pb)-Te alloys has a remarkable maximum and temperature coefficient of resistivity has large negative value around the equiatomic composition, suggesting that a kind of compound formation exists at this composition. The excess resistivities are interpreted in terms of resonance scattering by the compound of MTe(M=Sn, Pb) with a finite life time.

Thermodynamic properties of liquid Na-In alloys under high pressure

The authors report detailed data on the EMF of Na in molten Na-In alloys under high pressure. The measurements employed an electrochemical cell with beta -alumina as the electrolyte. The associated thermodynamic quantities of mixing such as the free energy Delta G, entropy Delta S, enthalpy Delta H, excess specific heat Delta Cp, excess volume Delta V, compressibility chi T and concentration-concentration fluctuation in the long-wavelength limit Scc(0), are obtained. From these, a kind of short-range order was found at the composition of Na4In under pressure, in addition to the other short-range orders, corresponding to beta and gamma phases in the solid state. Using Scc(0), Delta V and chi T, the various kinds of partial structure factors in the long-wavelength limit are also obtained.

Thermodynamic properties of liquid Na-VIB alloys

Abstract The thermodynamic quantities of mixing such as free energy ΔG, entropy ΔS and enthalpy ΔH of liquid Na-IVb alloys are discussed in view of formation of chemical complex. From these, the excess specific heat ΔC p as a function of temperature, which is resulted from the dissociation of chemical complex, is particularly concerned. The discrepancies in the compound-forming tendencies among liquid NaPb, NaSn and LiPb are also discussed.

Magnetic susceptibilities of liquid NaIVB alloys

Abstract The magnetic susceptibility of liquid NaIVb alloys has been measured as a function of temperature and concentration. The curve of susceptibility isotherm of liquid NaSn alloys exhibits a distinct minimum around the stoichiometric composition of Na 4 Sn 3 at liquids temperature. At the same composition, a remarkable temperature dependence has also been observed, and the minimum composition in the susceptibility isotherm shifts from Na 4 Sn 3 to NaSn at high temperature. This large temperature variation has been interpreted in terms of partial dissociation. While the curve of susceptibility isotherm of liquid NaPb shows a slightly negative deviation from the linearly interpolated line. The maximum deviations occurs at the composition of the Na 4 Pb.