Empty electronic states in solid and liquid nickel

The density of empty electronic states in solid and liquid nickel has been determined employing Auger electron appearance potential spectroscopy. The observed increase of the density-of-states at the Fermi level by a factor of 1.4 in the liquid is in good agreement with available resistivity data. An increase of d-holes from 0.6 to 1.0 upon fusion is also found and interpreted in terms of a reduced d-d-interaction in the liquid state.     

Thermopower and phase diagram for pure solid and liquid samarium

Measurements of thermopower, S, for pure solid and liquid samarium are reported. Trends in S and dS/dT for the liquid light lanthanide metals are discussed. Based on these thermopower results and other work, a proposed phase diagram for Sm is presented.     

Phase diagram of a two-dimensional electron system

The melting curve of the two-dimensional electron system is interpolated between the known classical and ground state limits. The coexistence curve encloses a finite solid-phase domain, as in the three-dimensional case.     

Phase diagram and interfacial characteristics in a binary system

Physics of the Solid State - The size effects on the composition of coexisting phases, the interfacial layer between them, and the interfacial tension in a binary system composed of a matrix and...     

Surface energies of metals in both liquid and solid states

Although during the last years one has seen a number of systematic studies of the surface energies of metals, the aim and the scientific meaning of this research is to establish a simple and a straightforward theoretical model to calculate accurately the mechanical and the thermodynamic properties of metal surfaces due to their important application in materials processes and in the understanding of a wide range of surface phenomena. Through extensive theoretical calculations of the surface tension of most of the liquid metals, we found that the fraction of broken bonds in liquid metals (f) is constant which is equal to 0.287. Using our estimated f value, the surface tension (γ_m), surface energy (γ_SV), surface excess entropy (−dγ/dT), surface excess enthalpy (H_s), coefficient of thermal expansion (α_m and α_b), sound velocity (c_m) and its temperature coefficient (−dc/dT) have been calculated for more than sixty metals. The results of the calculated quantities agree well with available experimental data.     

Phase states and dielectric properties of sodium-potassium niobate solid solutions

The temperature dependence of dielectric constant ? for single crystals of Na_1?xK_xNbO₃ (0.04?x?0.15) is studied for the first time. From the shape of the ?(T) anomalies corresponding to rotational phase transitions, the type of interaction between the order parameters and the polarization is determined. A phenomenological model is developed which adequately describes the experimentally observed sequence of high-temperature (T>300°C) phase transitions, the dielectric anomalies associated with these transitions, and the changes in the phase states under the action of external factors (pressure, electric field).     

Phase diagram and thermodynamic equilibrium in the Fe x TiSe2 system

Phase diagram has been refined by the quenching method; the phase composition has been monitored by NGR spectroscopy. The experimental data agree well with theoretical predictions on the relation of the phase diagram with the character of a chemical bond. It has been shown that the system is essentially nonquasi-binary because of the selenium exchange between the precipitated iron and the matrix lattice.     

低温下氦-3/氦-4液态混合物相平衡关系

在总结3He-4He混合溶液的相图研究并整理实验数据的基础上,确定了三临界点参数的精确值xt=0.674和Tt=0.867,提出了混合物超流相转变曲线和相分离曲线方程。结合实验数据对方程进行的精度分析表明,除个别实验点外,计算值与实验值百分比误差不超过2%,均在实验测量不确定度以内。通过发展得到的高精度方程绘制了可完整描述饱和蒸气压下3He-4He混合溶液的全局相图。     

Electrical conductivity and thermoelectric power of AgInSe2 in the solid and liquid states

The electrical conductivity and thermoelectric power of AgInSe₂ have been investigated as a function of temperature from 420°C to 950°C. Experimental data are analyzed in terms of a model developed for the density of states and electrical transport in solid amorphous semiconductors [1]. The activation energy calculated from electrical conductivity data is found to be 0.06 eV for the solid and 0.37 eV for the liquid phase. Moreover, the coefficient of the linear decrease of the energy gap with temperature was found to be 1.96×10^–4 eV/K.     

Comparative study of the heat capacity of icosahedral quasicrystals in solid and liquid states

The heat capacity of icosahedral quasicrystals Al₆₃Cu₂₅Fe₁₂ and Al₆₂Cu_25.5Fe_12.5 has been studied at high temperatures up to 1700 K, which is by almost 400 K higher than the melting point of the material. It has been shown that the melt exhibits an excess heat capacity with respect to that determined by the Dulong-Petit law and that is a direct extension of the excess heat capacity of the solid state. It has been concluded that the excess heat capacity is related, as a whole, to the short-range order in the quasicrystal structure. This circumstance allows the identification of the orbital hybridization as the most probable mechanism of formation of the pseudogap in the electronic structure of the quasicrystals.     

铋的固相及液相多相状态方程研究

铋在高温高压下存在一系列复杂相结构,相变伴随着密度、内能等物理性质的改变.采用半经验三项式Helmholtz自由能表达式,构建了铋的五个固相及液相的多相状态方程,其中离子热振动自由能计算基于经典平均场理论给出的平均场势函数模型开展.研究结果表明,状态方程计算给出的铋的相图、等温压缩线、液相的温度-密度曲线以及冲击Hugoniot线等均与实验测量符合较好,故可认为本文构建的铋的多相状态方程具有良好的参数合理性以及模型适用性.     

Phase diagram and physical properties of the sodium niobate-lithium niobate-cadmium niobate three-component system

The phase diagram of the (Na,Li,Cd_0.5)NbO₃ ternary system is refined. The electrical properties of solid solutions over a broad range of the component concentrations were studied. The compositions promising for high-temperature transducers were obtained.     

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.