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In this review paper, using the example of AM–Pb and AM–Bi melts (AM is an alkali metal), modern ideas on the nature of chemical short-range order in liquid metal systems with partial ionic bonding are briefly presented. Generalization and analysis of the experimental data obtained by the authors on the volumetric properties and mutual diffusion in liquid alloys of alkali metals with lead and bismuth have been carried out. The behavior of these properties is shown to generally agree with existing simple models that assume the presence of ionic complexes in melts, which gradually dissociate with increasing temperature. At the same time, the need to refine the structure of polyanionic complexes in liquid AM–Bi systems is confirmed. [ABSTRACT FROM AUTHOR]

Using an isothermal drop calorimeter, the enthalpy increment of the Na15Pb4 and Na50Pb50 alloys was measured and the heat capacity was determined in the temperature range of 420–1075 K, including the solid and liquid states. It has been established that the values of the heat capacity of melts significantly exceed the calculations of this value according to the laws for an ideal solution, and this difference decreases with increasing temperature. The obtained results confirm the currently existing ideas that various complexes with a partially ionic character of the interatomic interaction are formed in the melts of alkali metals with lead systems. [ABSTRACT FROM AUTHOR]

Using an ultrasonic interferometer in the temperature range from 293 to 393 K at pressures from 0.13 to 1.5–2.8 MPa, the speed of sound (U) was measured in helium-xenon gas mixtures with a helium content of 60.34; 71.72 and 85.32 at. %. The measurement errors of temperature, pressure, and speed of sound were ±20 mK, ±4 kPa, and ± (0.15–0.30) %, respectively. By approximating the experimental data for each composition, equations were obtained to describe changes of the speed of sound as a function of pressure and temperature over the entire measurement range. The existing reference and experimental data on the speed of sound in inert gases and He-Xe mixtures were analyzed. A method for calculating U of mixtures with a helium content above 71.7 at. % He to a temperature of 1500 K and a pressure of up to 7 MPa was developed. [ABSTRACT FROM AUTHOR]

The volumetric properties of liquid indium-lead alloys containing 20 and 33 at. % Pb have been measured using gamma-ray attenuation technique at temperatures from the liquidus line to 880 K. The density changes of these alloys during solid–liquid phase transition have been calculated. The obtained experimental values of the molar volume and the volumetric thermal expansion coefficient of melts and the results of calculations according to the laws for an ideal solution and data of other authors have been compared. [ABSTRACT FROM AUTHOR]

Thermal conductivity of a Novec 7100 fluid sample was measured by the steady-state method of coaxial cylinders. Experiments were performed in the temperature range 350–385 K and pressure range 0.12–0.21 MPa. The error for experimental data on thermal conductivity is about 1.5–2.5 %. The error in measuring temperature and pressure was less than 0.05 K and 4 kPa, correspondingly. The general equation for calculating the thermal conductivity as a function of pressure and temperature was formulated. Thermal conductivity was defined for the ideal gas state. A previously developed approach was tested in application for a single-measurement prediction of thermal conductivity. [ABSTRACT FROM AUTHOR]

The density of liquid mixtures of lithium and potassium fluorides with a content of 51.2 and 71.1 mol % LiF was measured using gamma-ray attenuation technique in the temperature range from liquidus to 1000–1190 K. For a mixture of near-eutectic composition (51.2 mol % LiF), the relative density change during the solid–liquid phase transition and the density in the solid state near the melting point were directly determined for the first time. The concentration dependences of the molar volume and volumetric coefficient of thermal expansion for the LiF–KF liquid system were plotted on the basis of the experimental and literature data. The obtained dependences were found to be close to the concentration dependences of the corresponding volumetric properties for ideal solutions. [ABSTRACT FROM AUTHOR]

The results of an experimental study of the thermal expansion of gallium garnets Gd3Ga5O12, Gd3.04Sc1.8Ga3.16O12, and Ca3Nb1.5Ga3.5O12 in a wide temperature range (293.15–1473 K) are presented. A noticeable effect of niobium in the structure of gallium garnets on the thermal expansion coefficient has been found. The temperature dependences of the volumetric properties have been obtained. [ABSTRACT FROM AUTHOR]

Using the method of differential scanning calorimetry, the heat capacity of Mg-Ca alloys containing 10.50, 33.34, and 73.00 at. % Ca, being promising for various practical applications (biocompatible and biodegradable alloys, ultralight construction materials, anode materials, hydrogen absorbent materials, etc.) has been studied experimentally. New reliable experimental results on the heat capacity in the temperature range of 190–576÷692 K of the solid state have been obtained. The estimated errors of the received data were 2–3 %. The reference table for temperature dependences of heat capacity of Mg-Ca alloys has been compiled. It has been established, that over a wide temperature range the heat capacity of solid magnesium-calcium alloys can be estimated with high accuracy using the Neumann–Kopp rule. [ABSTRACT FROM AUTHOR]

The density of liquid lithium fluoride and an eutectic mixture of lithium fluoride and sodium fluoride (with a content of 39 mol % NaF) was measured by the gamma-ray attenuation method in the temperature range from liquidus to ∼1280 K. The obtained results were compared with the available literature data. The study of liquid eutectic LiF–NaF was carried out in a much wider temperature range compared to other authors, and the obtained values of the volumetric coefficient of thermal expansion turned out to be the most reliable. [ABSTRACT FROM AUTHOR]

An experimental study of the heat capacity of gadolinium-scandium-gallium and calcium-niobium-gallium garnets widely used in laser technology and microelectronics was carried out by the method of differential scanning calorimetry. New experimental results on the specific isobaric heat capacity in the temperature range of 300–1270 K were obtained; approximation equations and a table of recommended values for scientific and practical use were developed on their basis. The comparison with the known literature data was carried out. The estimated error of the data obtained was 2–4%. [ABSTRACT FROM AUTHOR]

The thermal conductivity of the R-32/R-125 (15/85) mixture was investigated in the range of temperatures of 305–411 K and pressures of 0.1–1.8 MPa. Measurements were carried out by the stationary method of coaxial cylinders. The error of the experimental data on thermal conductivity was 1.5–2.5 %, and the measurement errors of temperature and pressure did not exceed 0.05 K and 4 kPa, respectively. A generalizing equation for calculating the thermal conductivity as a function of pressure and temperature was obtained. The thermal conductivity on the dew line and in the ideal gas state was determined. [ABSTRACT FROM AUTHOR]

The density and thermal expansion coefficients of polycrystalline, liquid, and amorphous phases of Fe60Co20Si8B12 alloy in the temperature range of 293–1650 K were measured by the monochromatic gamma-ray attenuation technique. The features of crystallization of the melt and amorphous film were investigated. Reference tables of properties were developed, their errors were estimated, and approximation equations were obtained. [ABSTRACT FROM AUTHOR]

The transfer properties of a congruently melting Mg-Li alloy with a lithium content of 30 at. %, considered as a promising ultralight structural material for the aerospace industry, have been studied experimentally. New experimental data on thermal diffusivity (a) and thermal conductivity (λ) have been obtained in the temperature range of 293–777 K with estimated errors of 2–4 % and 3–5 %, respectively. The results have been compared with the known literature data on thermal conductivity of Mg-Li system alloys. A table of recommended temperature dependences for a and λ of the studied composition has been developed. [ABSTRACT FROM AUTHOR]

The results of a dilatometric study of the linear thermal expansion coefficient of superconducting tapes "Amperium" and "SuperOx" in the temperature range of 100–370 K are presented. Temperature dependences are obtained, and reference tables of recommended values of thermal properties are calculated. The effect of film deformation on the measurement results is investigated. The design of the sample holder, eliminating the tape bending is developed. The linear thermal expansion coefficient of the tapes is compared with the thermal expansion of the metal layers of the films. It is shown that the difference in the relative expansion in the temperature range from 100 to 293 K does not exceed 0.05 %. [ABSTRACT FROM AUTHOR]

A comprehensive experimental study of the thermophysical properties of the zirconium alloy E-110 (Zr-1 at. % Nb), which is used as a structural material for fuel rods of modern reactors, has been carried out. New experimental data on the thermal diffusivity a and the isobaric heat capacity cp in the temperature range of 293–1275 K have been obtained. Based on the measurement results, the thermal conductivity λ for the α-phase of the alloy has been calculated. The estimated error of the obtained data is 2–4 %, 3–5 %, and 2–3 % for a, α, and cp, respectively. The comparison with the known literature data has been carried out. A table of recommended temperature dependences of all the studied properties has been developed. [ABSTRACT FROM AUTHOR]

The experimental results obtained by the dilatometric method for thermal expansion of the Hastelloy C276 alloy in the temperature range of 100–370 K are presented. Temperature dependences of thermal properties have been obtained. The obtained results are compared with the data for thermal expansion of superconducting tapes of the "Amperium" and "SuperOx" brands. [ABSTRACT FROM AUTHOR]

The solubility of heavy alkali metals in liquid lithium was investigated at temperatures from the melting point of Li to ∼1200 K by the method of gamma-raying of liquid samples by a narrow beam of gamma radiation. Even at high temperatures, the solubility of K, Rb, and Cs in liquid lithium has been found to be very insignificant. The potassium content in the lithium-rich phase is 0.2 at. % at 850 K and 3.4 at. % at 1212 K. The solubility of rubidium in liquid lithium, within the measurement error, is zero at temperatures from 453 K (melting point of Li) to 800 K and reaches only 0.5 at. % at 1172 K. Cesium is practically insoluble in liquid lithium up to a temperature of 1150 K. [ABSTRACT FROM AUTHOR]

Using the laser flash method and the drop method, the thermal conductivity and the enthalpy increment of the eutectic K-Pb alloy (with a Pb content of 90.7 at.%) were measured in the temperature range from the liquidus point up to 1077–1175 K. The specific heat capacity and thermal diffusivity of the alloy were calculated. Approximation equations for the studied properties were obtained, and a table of reference data was developed. It was shown that the thermal conductivity of the liquid eutectic is less than that of pure lead and increases with temperature. [ABSTRACT FROM AUTHOR]

Using the laser flash method the thermal conductivity of the Rb-Bi liquid alloy with a bismuth content of 27 at. % was measured in the temperature range from the liquidus point to 1173 K. Approximation equations for thermal conductivity and thermal diffusivity have been obtained, and a table of reference data has been developed. An analysis of the measurement results confirms the existing assumption of the presence of intermetallic complexes with a partially ionic nature of the interatomic interaction in Rb-Bi melts. [ABSTRACT FROM AUTHOR]

The work is devoted to the study of temperature dependences of thermal conductivity (T = 300–770 K) of polycrystallic samples of solid solutions based on gadolinium and dysprosium sulfides of the compositions: γ-GdxDy1−xS1.49 (x = 0.1, 0.2, 0.3, 0.4). It has been found that the morphological features of samples, namely, the specific surface area of crystallites, which causes a change in the number of deformation centers, determines the value of the thermal conductivity of γ-GdxDy1−xS1.49 solid solutions. The presence of an abnormal decrease in thermal conductivity for the composition of x = 0.2 has been established. When the temperature increases to 770 K, this anomaly decreases slightly. The minimum value of the thermal conductivity coefficient of 0.68 ± 0.03 W/(m·K) is reached for the composition under consideration at 770 K. [ABSTRACT FROM AUTHOR]

The enthalpy of the CsBi alloy in the temperature range of 432–1127 K of the solid and liquid states has been measured by the mixing method on a massive isoperibolic calorimeter. Approximation equations have been obtained, and the isobaric heat capacity and enthalpy changes on phase transitions have been determined. The estimated errors of the data on enthalpy and heat capacity of the melt are 0.75 and 1.5–2.0%, respectively. The enthalpy of the alloy formation in the liquid state has been determined. The obtained results have been compared with the calculations based on the laws of ideal solutions. [ABSTRACT FROM AUTHOR]

The laser-pulse method was used to measure the thermal diffusivity of La98.8Fe1.2 alloy in the temperature range of 293–1623 K of the solid and liquid states, including the regions of phase transformations. The measurement uncertainties of the heat transfer coefficients were ± (3–6) %. Approximating equations and tables of reference data on thermal conductivity and thermal diffusivity of La98.8Fe1.2 alloy have been obtained for scientific and practical use. A comparison of measurement results with known literature data on thermal diffusivity of pure lanthanum has been carried out. [ABSTRACT FROM AUTHOR]

The density and thermal expansion of the solid and liquid Inconel 718 alloy are measured by the dilatometer method and gamma-ray attenuation technique over the temperature range 293.15–1730 K. The density change during the solid-liquid phase transition is directly measured. A comparison of the obtained results with literature data is carried out. [ABSTRACT FROM AUTHOR]

The results of a dilatometric study of the linear thermal expansion coefficient (LTEC) of polycrystalline samarium in the temperature range of 110-1050 K are presented. Temperature dependences have been obtained and reference tables of recommended values of thermal properties for the 110-1900 K interval of its solid and liquid states have been calculated. The nature of the LTEC change in the regions of phase transformations of the first and second kinds has been established. The critical indices of the linear thermal expansion coefficient at the Neel point have been determined. [ABSTRACT FROM AUTHOR]

The thermal conductivity and the thermal diffusivity coefficients of samarium have been measured by the laser flash method in the temperature interval of 293-1773 K in solid and liquid states including the regions of phase transitions. The measurement errors of the heat transfer coefficients were ±(3-6)%. The approximation equations and the tables of reference data for the temperature dependence of properties have been obtained. The obtained results have been compared with the available literature data. [ABSTRACT FROM AUTHOR]

Enthalpy of solid and liquid intermetallic compound CsBi2 in the temperature range of 430-1225 K was measured by massive isothermal drop calorimeter. Approximation equations were obtained, and isobaric heat capacity and enthalpy change on melting were determined. The tables of recommended values of caloric properties in the range from 298.15 K to 1225 K were developed. The experimental uncertainty of enthalpy and heat capacity measurements were estimated to be within 0.35 and 1.0%, respectively. The obtained results were compared with the calculations according to the laws of ideal solutions. [ABSTRACT FROM AUTHOR]

The thermal conductivity λ and the thermal diffusivity a of liquid rubidium were measured by the laser flash method in the temperature interval from the melting point up to 873 K. The measurement error was 4-6%. The data of this paper were compared with the results of other authors. Approximation equations and the table of reference values for the temperature dependence of λ and a have been obtained. The dependence of the Lorentz number on temperature has been calculated. [ABSTRACT FROM AUTHOR]

The speed of sound of the gaseous mixed refrigerant R-134a (57.24 wt.%) - R-227ea (42.76 wt. %) was investigated by the method of ultrasonic interferometer in the temperature range from 293 to 373 K and at pressures from 0.08 to 0.97 MPa. The measurement errors of temperature, pressure, and speed of sound were ±20 mK, ±4 kPa, and ±(0.20-0.35) %, respectively. Approximation dependences of the speed of sound on five isotherms have been obtained, and the experimental data have been compared with calculations using the REFPROP program. [ABSTRACT FROM AUTHOR]

The density and the thermal expansion of liquid lithium-lead alloys with Pb content of 83.0 and 84.3 at. % was measured using gamma-ray attenuation technique over the temperature range from liquidus to 1000 K. The density change during solid-liquid phase transition was directly measured for the first time for Li15.7Pb84.3 alloy. A comparison of the obtained results with literature data has been carried out. [ABSTRACT FROM AUTHOR]