Density of liquid antimony-zinc alloys

The density of liquid antimony-zinc alloys has been measured over the whole phase diagram. The isothermal variation of density with composition exhibits a monotonic behaviour in contrast to earlier results. The excess volume is positive with a maximum for 60 at% zinc.     

Positron trapping in the liquid and solid copper alloys

The peak counting rates of γ?γ angular correlation curves of positron annihilation (PCAC) in the liquid state fitted well to the straight line which had the same slope of the temperature dependence of the PCAC's attributed to the free annihilation in the solid state, for the Cu-8Ge and Cu-10.5Ge alloys and other copper solid solutions. The results of the positron trapping model fitting suggest the possibility that the positron in the liquid state repels the surrounding ions.     

Density and related thermophysical properties of metastable liquid Ni-Cu-Fe ternary alloys

The densities of liquid Ni-Cu-Fe ternary alloy system were investigated by molecular dynamics method in combination with a MEAM (Modified Embedded Atom Method) potential model. The temperature range is from 1000 to 2200 K, including both a broad superheating range and a large undercooled regime. The densities of six Ni100−2xCuxFex alloys (x=0,10,20,30,40,50) decrease linearly with the rise of temperature at the superheated and undercooled states, and increase with the enhancement of Ni content. Among the simulated alloys, the densities of only liquid pure Ni and Ni₆₀Cu₂₀Fe₂₀ alloy are available in literatures, which are in good agreement with the calculated values. According to the relationship between the excessive volume and the alloy composition, it can be deduced that Ni100−2xCuxFex alloys deviate from ideal solution. Moreover, a comparison was also performed between the calculated results and the approximated values by Neumann-Kopp's rule. Based on the obtained density data, the thermal expansion coefficients are also derived. It firstly decreases to a minimum value, and then displays a rise with the increase of Ni content.     

Constitution and magnetic properties of Ni-Mn-Sn alloys - solid and liquid state

Ternary Ni₅₀Mn_50-xSn_x alloys have been studied by means of the magnetothermal analysis. The high temperature phase of the Ni₂MnSn Heusler alloy is obtained directly from the melt (structure of B2 type). From the paramagnetic behaviour of the Heusler alloy in the liquid as well as solid states, the same magneton number $\text{n′}{}_{\mathrm{<mtext>eff</mtext>}}\text{? 5}$ per Mn atom results. At lower temperatures this phase forms the L2₁ structure and shows a resulting ferromagnetic magneton number $\text{n}{}_{\mathrm{rmf}}\text{? 4}$, a value which is well known.     

Magnetic susceptibility and electronic structure of solid and liquid Co,V alloys and Ni,V alloys

The temperature and concentration dependence of the magnetic susceptibility of Co, V and Ni, V alloys has been investigated in a wide temperature (800–1800°C) and concentration (0–50 at.% V) range. The concentration dependence of is on the whole monotonic, but it exhibits extrema in the region of low vanadium concentrations (up to 2%). The results obtained are discussed on the basis of the band model taking into consideration the possibility of the formation of localized states at vanadium atoms in some narrow concentration range.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 86–91, April, 1979.     

Density dependence of mean kinetic energy in liquid and solid hydrogen at 19.3 K

We have measured, using the TOSCA spectrometer at ISIS, the inelastic incoherent neutron scattering spectrum of liquid and solid para-hydrogen along the T = 19.3 K isotherm. From the high-energy region of the spectrum, where the Impulse Approximation for the Centre of Mass motion applies, we have been able to extract the mean translational kinetic energy, which, as expected, turns out rather different from the classical value and density dependent. We find that the density behaviours in the liquid and the solid phase are slightly different. This confirms a similar feature already observed in liquid and solid helium at T = 6.1 K [M. Celli, M. Zoppi, J. Mayers, Phys. Rev. B 58, 242 (1998)]. The spectra from the solid phase have been also analysed in the low-energy region and allowed us to derive the Debye-Waller factor of solid para-hydrogen as a function of density. The comparison with the available experimental data in the literature is rather good and confirms the excellent performances of TOSCA in the spectroscopic analysis of the condensed phases of para-hydrogen.     

Thermal conductivity of alloys of the systems Sn-Pb and Sn-In in the solid and liquid states

Results are presented of the measurement of the thermal conductivity of alloys of the eutectic systems Sn-Pb and Sn-In in the solid and liquid phases from 100 to 600 °C by a steady-state method. The thermal conductivity of the investigated alloys depends linearly on the temperature. The contribution of the phonon and electron components to the thermal conductivity are estimated. It is concluded from the results that the presence of foreign atoms in the investigated alloys has no significant effect on the thermal conductivity, which is determined principally by the scattering of the electrons by the phonons.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 25–28, December, 1970.     

Density and surface tension polyterms of lead-based alloys

Experimental data are presented on the density and surface tension of lead-bismuth and leadcalcium melts obtained using the sessile drop method over a broad range of temperatures in a helium atmosphere.     

The resistivity of liquid alloys

The theory of the resistivity of dilute binary alloys in the liquid state is briefly reviewed, and its application to certain systems based upon the alkali metals, especially lithium containing small amounts of magnesium, is discussed in quantitative detail. There appears to be a serious discrepancy in the case of Li-Mg, which shows up especially in the temperature variation of the resistivity. It is shown that the Born approximation, upon which the theory is based, may not be entirely valid, but this does not serve to dispose of the discrepancy.

The paper includes some remarks about the theory of the Knight shift in liquid alloys.     

Density of states in ferromagnetic NiCu alloys

We have calculated the concentration dependence of the density of states at Fermi level in ferromagnetic NiCu alloys using a two-band model Hamiltonian and the coherent potential theory. Good agreement with experimental data has been obtained.     

Density wave theory of freezing and the solid

The theory of the liquid to solid transition, in three as well as in two dimensions, is reviewed. The transition can be viewed either as the melting of the solid due to phonon or defect proliferation instabilities or alternatively as freezing of the liquid into a density wave state with crystalline symmetry. A theory due to Yussouff and the author, based on the latter idea, is discussed and its predictions are compared with experiment. It is shown that the theory leads to a new approach to the properties of a deformed (e.g., sheared) solid and of defects such as grain boundaries and dislocations in a solid. The approach brings out explicitly the structural nature of these properties, and is not restricted to small deviations from perfect periodicity (harmonic approximation) since the solid, the liquid and anything in between can be handled theoretically.     

Mixing in binary liquid alloys

A review of some experimental results and theories of mixing in binary metallic systems indicating properties of the constituents of importance and ways in which the existing theories may be adapted to describe some of the results.     

Interatomic distances in liquid metals and alloys

X-ray diffraction patterns of liquid tin and liquid mercury are unlike those of simple liquid metals such as Na, K, Cu and Au in that the intensity patterns show considerable asymmetry, or a distinct shoulder, on the high angle side of the main peak. The position of the main peak gives the average interatomic distance in the melt; for Sn and Hg the additional detail of the pattern gives a special close distance of approach. It is shown that this distance is related to that occurring in the low temperature allotropes of the solid metals.

In diffraction patterns of liquids of the Au-Sn alloy system the main intensity peak is resolved into two distinct maxima. One component occurs at a position corresponding to a simple random mixture of the component elements, the other to a close interatomic distance. The relative heights of the peaks are composition dependent. The close-packed component persists across the diagram, being strongest at composition Au₃Sn and decreasing to a shoulder at pure Sn. As for Sn and Hg the short distance can be correlated with a short distance occurring in the crystalline solids of the system.

A similar scheme may be applied to the systems Cu-Sn, Au-Ga and Au-In where double-headed diffraction patterns have been observed in the liquids.

It is postulated that the origin of the close distance occurring in the liquid in each system is the same as that of the strong bond existing in the crystalline compounds.     

Electrical resistivity of liquid gold-silicon alloys

The electrical resistivity of liquid Au_1?xSi_x alloys was measured in the gold-rich concentration range, 0.16 ? x ? 0.40, as a function of temperature and composition. In this region the temperature coefficients of the resistivity is negative. The resistivities and temperature coefficients are compared with recent data on amorphous sputtered films; for x ? 0.31 the resistivities of the films are in agreement with those of the liquids within the accuracy of the measurements. The results can be interpreted in terms of the Ziman theory.