Molten InSb Research Articles

Thermal properties of molten InSb, GaSb, and InxGa1−xSb alloy semiconductor materials in preparation for crystal growth experiments on the international space station

The thermal properties of InSb, GaSb and InxGa1−xSb, such as the viscosity, wetting property, and evaporation rate, were investigated in preparation for the crystal growth experiment on the International Space Station (ISS). The viscosity of InGaSb, which is an essential property for numerical modeling of crystal growth, was evaluated. In addition, the wetting properties between molten InxGa1−xSb and quartz, BN, graphite, and C-103 materials were investigated. The evaporation rate of molten InxGa1−xSb was measured to determine the affinity of different sample configurations. From the measurements, it was found that the viscosity of InxGa1−xSb was between that of InSb and GaSb. The degree of wetting reaction between molten InxGa1−xSb and the C-103 substrate was very high, whereas that between molten InxGa1−xSb and quartz, BN, and graphite substrates was very low. The results suggest that BN and graphite can be used as materials to cover InSb and GaSb samples inside a quartz ampoule during the microgravity experiments. In addition, the difference of the evaporation rate of molten InxGa1−xSb, GaSb, and InSb was small at low, and large at high temperature.

Effect of residual gaseous impurities on the dewetting of antimonide melts in fused silica crucibles in the case of bulk crystal growth

A Bridgman set-up has been modified to perform the contactless growth (“dewetting”) of gallium and indium antimonide compounds in fused silica crucibles. According to wetting parameters measured by the sessile drop method given in the literature, both molten InSb and GaSb compounds are considered as non-reactive with silica substrates. A detailed description of the experimental set-up is presented. Each polycrystalline sample is inserted in a sealed silica crucible that is backfilled with industrial argon containing a few ppm of oxygen. Under similar experimental conditions, the dewetted growth of GaSb is much easier to obtain than that for InSb. The presence of residual impurities such as oxygen in the backfilling gas appears to enhance the occurrence of the phenomenon for GaSb.

Picosecond Melting of Ice by an Infrared Laser Pulse: A Simulation Study

X-ray lasers bring us into a new world in photon science by delivering extraordinarily intense beams of x-rays in very short bursts that can be more than ten billion times brighter than pulses from other x-ray sources. These lasers find applications in sciences ranging from astrophysics to structural biology, and could allow us to obtain images of single macromolecules when these are injected into the x-ray beam. A macromolecule injected into vacuum in a microdroplet will be affected by evaporation and by the dynamics of the carrier liquid before being hit by the x-ray pulse. Simulations of neutral and charged water droplets were performed to predict structural changes and changes of temperature due to evaporation. The results are discussed in the aspect of single molecule imaging. Further studies show ionization caused by the intense x-ray radiation. These simulations reveal the development of secondary electron cascades in water. Other studies show the development of these cascades in KI and CsI where experimental data exist. The results are in agreement with observation, and show the temporal, spatial and energetic evolution of secondary electron cascades in the sample. X-ray diffraction is sensitive to structural changes on the length scale of chemical bonds. Using a short infrared pump pulse to trigger structural changes, and a short x-ray pulse for probing it, these changes can be studied with a temporal resolution similar to the pulse lengths. Time resolved diffraction experiments were performed on a phase transition during resolidification of a non-thermally molten InSb crystal. The experiment reveals the dynamics of crystal regrowth. Computer simulations were performed on the infrared laser-induced melting of bulk ice, giving a comprehension of the dynamics and the wavelength dependence of melting. These studies form a basis for planning experiments with x-ray lasers.

Thermal Conductivity Measurement of Molten Indium Antimonide Using Hot-Disk Method in Short-Duration Microgravity

The thermal conductivity of molten indium antimonide (InSb) was measured using the hot-disk method in short-duration microgravity. The hot-disk sensor was made of molybdenum foil (thickness, 20 µm; radius of sensor region, 3.05 mm) cut in a conducting pattern and placed between two aluminum nitride (AlN) plates (plate thickness, 0.05 mm). Because AlN had not chemically reacted with molten InSb, the molybdenum foil in the hot-disk sensor was completely protected against the molten InSb. The thermal conductivity of molten InSb was measured during short-duration microgravity using a 10 m drop tower to confirm the thermal convection effect during the measurement. The thermal conductivity of molten InSb measured in microgravity was 17.3 W·m-1·K-1 at 824 K and increased with temperature. The thermal conductivities measured in normal gravity were found to be higher than those measured in microgravity. The thermal conductivity of molten InSb at melting point (798 K), i.e., 16.5 W·m-1·K-1, was obtained by the extrapolation of the thermal conductivity of the molten InSb against temperature.

Influence of oxygen, hydrogen, helium, argon and vacuum on the surface behavior of molten InSb, other semiconductors, and metals on silica

Sessile drop experiments were performed on molten indium antimonide on clean quartz (fused silica) surfaces. A cell was constructed through which argon, helium, oxygen, hydrogen or a mixture of these was flowed at 600 °C. Some of the InSb was doped with 0.1% Ga. The surface tension σ of oxide-free molten InSb was smaller in Ar than in He, may have increased with increasing O 2 in the gas, and was not influenced by Ga or H 2. The contact angle θ on silica was higher in the presence of Ar, was lowered by O 2, and was not influenced by H 2 or Ga. The work of adhesion W and the surface energy σ sv of the silica were higher in He than in Ar. The surface remained free of solid oxide only in flowing gas containing ⩽0.8 ppm O 2. This behavior is attributed to reaction of O 2 at the surface of the melt to form In 2O gas. When solid oxide formed on Ga-doped material, it was strongly enriched in Ga, with the Ga/In ratio increasing with the concentration of O 2 in the gas. Examination of published sessile-drop results for liquid metals and semiconductors on silica revealed that W and σ sv were highest for reactive melts, in which SiO 2 dissolves. For non-reactive melts, W and σ sv were lower and θ higher in a gas than in a vacuum, regardless of whether the experiments had been carried out in sealed ampoules, a flowing gas, or dynamic vacuum. The implication is that the surface of silica was different in a vacuum than in a gas at ∼1 bar.

Studies of resolidification of non-thermally molten InSb using time-resolved X-ray diffraction

We have used time-resolved X-ray diffraction to monitor the resolidification process of molten InSb. Melting was induced by an ultra-short laser pulse and the measurement conducted in a high-repetition-rate multishot experiment. The method gives direct information about the nature of the transient regrowth and permanently damaged layers. It does not rely on models based on surface reflectivity or second harmonic generation (SHG). The measured resolidification process has been modeled with a 1-D thermodynamic heat-conduction model. Important parameters like sample temperature, melting depth and amorphous surface layer thickness come directly out of the data, while mosaicity of the sample and free carrier density can be quantified by comparing with models. Melt depths up to 80 nm have been observed and regrowth velocities in the range 2-8 m/s have been measured.

In-situ XAFS studies on local structures of molten InSb compounds

The local structures of semiconductor InSb compound have been studied by in-situ XAFS in the temperature range of 300 and 823 K. Reverse Monte Carlo calculation is used to simultaneously fit both In and Sb K-edge EXAFS functions kχ(k) of InSb compound. The fitting results indicate that the average bond length R1 (2.80 Å) and the average coordination number N1 (4.0) of the first In-Sb (or Sb-In) shell of InSb (723 K) are similar to those (2.79 Å, 4.0) of crystalline InSb (300 K) with a zinc-blende structure, in spite of InSb compound possessing a large thermal disorder degree at 723 K. At the temperature of 828 K (Tm(InSb) = 798 K), the R1 and N1 of the first In-Sb shell are 2.90 Å and 5.8, and the R1 and N1 of the first Sb-In shell are 2.90 Å, and 5.5 for molten InSb, respectively. For molten InSb (828 K), the coordination numbers of the In-Sb (or Sb-In) first shell are mostly 5 and 6, and a few percent of In-In (or Sb-Sb) coordination appears in the first shell. It implies that the tetrahedron structures of the In-Sb (or Sb-In) covalent bonds of InSb compound have been destroyed in the liquid state.

Viscosity of Molten GaSb and InSb

Viscosities of molten GaSb and InSb as III–V compound semiconductors were measured using an oscillating viscometer to study the thermophysical properties of semiconductor melts. A specially designed quartz crucible was used to prevent the evaporation of Sb from the melts. The measurements were performed in the temperature ranges from the melting point to about 1490 K for GaSb and from supercooled temperatures to about 1340 K for InSb. The viscosities obtained for both GaSb and InSb showed good Arrhenius linearity despite their wide temperature ranges. The activation energies of GaSb and InSb were almost the same, although the absolute viscosity of GaSb was slightly higher than that of InSb. It was concluded that most semiconductors including Si and Ge show Arrhenius behavior and have a low viscosity. The reason for the low viscosity is considered to be related to their melt structure, which may be similar to that of molten metals with low melting points.

OBTAINING OF AMORPHOUS In-Sb-Se ALLOYS

Tammann curves I(T), U(T) are calculated within kinetic approach, and parameters, which are characterize kinetic of steady - state and non-steady-state nucleation at maximum crystallization temperature for the molten InSb, Sb 2 Se 3 and Sb-Se alloys. Limits of glass - formation region for the In - Sb - Se alloys are definite in condition of hard quench. There are researched the characteristical temperatures of the thermo - effects Sb - Se alloys. Critical cooling rates, which are calculated theoretically, are near of the experimental data.

The anomalous temperature dependence of the heat capacity of molten InSb in the vicinity of the melting temperature

Indium antimonide melts according to the semiconductor-metal type. Investigations and analysis of some physical properties of its melts are evidences of structural changes in the melt at temperature somewhat higher than its melting point. This phenomenon was called "after-melting". Data on detecting this effect studying the heat capacity of the melt are rather contradictory. Our determination of the InSb melt heat capacity confirmed the anomalous temperature dependence in the temperature range of 798-853 K. The results were analyzed by calculating the determinant of thermodynamic stability and the isodynamic coefficients of stability.

Thermophysical property measurements on molten semiconductors using 10-s microgravity in a drop shaft

The effectiveness of 10-s microgravity on thermophysical property measurements on molten materials, such as molten semiconductors, is discussed. The thermal conductivity of molten InSb was successfully measured under microgravity conditions on board the German sounding rocket TEXUS and in a drop shaft in Hokkaido, Japan. Surface tension measurements using an oscillating drop method was attempted in low gravity using a parabolic flight of the NASA KC-135 aircraft. Combined levitation and microgravity, which can provide a contamination-free and undercooled condition. is recommended as a novel approach to obtain missing thermophysical property data on undercooled melts of semiconductors.

微小重力状態を利用した高温融体の熱伝導率測定技術

微小重力状態を利用した高温融体の熱伝導率測定技術

Measurement of the thermal conductivity of molten InSb under microgravity

Thermal conductivity of molten InSb was measured on board the TEXUS-24 sounding rocket by the transient hot-wire method using the originally designed thermal conductivity measurement facility (TCMF). Measurements made through this facility were affected by natural convection on the ground. This natural convection was confirmed to be sufficiently suppressed during a microgravity environment. The thermal conductivity of molten InSb was 15.8 and 18.2 W·m−1·K−1 at 830 and 890 K, respectively.

Thermal conductivity of GaSb and InSb in solid and liquid states

Thermal conductivities of InSb and GaSb in solid and liquid states were measured with a ceramic probe. Thermal conductivities at melting points were about 17.7 (W/mK) at 803 K for molten InSb and 21.7 (W/mK) at 993 K for molten GaSb. Thermal conductivities were slightly increased with increasing temperature in liquid state. Lorenz numbers in liquid state were 2.34×10−8 (WΩ/K2) at 803 K for InSb and 2.07×10−8 (WΩ/K2) at 993 K for GaSb.

浮遊帯域溶融法によるInSb単結晶の成長

This paper shows the potential applications of the floating zone method to the growth of single crystals of InSb whose melts have high specific gravity and low surface tension.The maximum diameter of the single crystals that can be obtained by the method about 5 mm, because the molten zones with sizes up to 5 mm in diameter can only be sustained against the gravitational froce. The most suitable conditions for growth of the InSb single crystals were described. This paper also presents a new method to measure the surface tension from the equilibrium shape of the molten zones. By the method the surface tension of the molten InSb is determined to be 0.290 N/m.The single crystals obtained are characterized by X-ray topography, whose imperfections are mainly twining, stacking faults and dislocation loops.

Measurement of the thermal conductivity of molten semiconductors

The thermal conductivity of molten InSb in the temperature range between 800 and 870 K was measured by the transient hot-wire method using a ceramic probe. The probe was fabricated from a tungsten wire printed on an alumina substrate and coated with a thin alumina layer. The thermal conductivity was found to be about 18 W· m−·K−at the melting point and increased moderately with increasing temperature. The thermal conductivity of alumina used as the substrate for the probe was also measured in the same temperature range.

Increase of effective viscosity of molten GaAs and InSb under an axial magnetic field

We have measured the effective dynamic viscosity of molten GaAs and InSb as a function of axial magnetic field by the oscillating vessel method. Effective viscosity of these semiconductor melts is observed to increase with the axial magnetic field intensity in the range of 0 to 5 kG.

Thermodynamische eigenschaften flüssiger legierungen der systeme InSbPb und InSbBi

For the exact determination of relatively small mixing enthalpies a high temperature calorimeter has been developed which permits measurements up to 1320 K. With this calorimeter, the enthalpy changes on mixing molten InSb with liquid lead and liquid bismuth, respectively, have been determined. Furthermore, the liquidus curve in the pseudobinary system InSbPb has been defined. The results are discussed with the aid of the regular solution model and also assuming the existence of InSb associates in the ternary melt. The thermodynamic properties of the liquid InSbPb and InSbBi alloys are distinctly defined by the formation of associates.