Indium melting temperature

Continually cycle indium from 120°C to 200°C at 10°C/min after the cooling system has been turned on. Measure the melting temperature and enthalpy on each cycle until the results are repeatable. 

The direct plasma reduction of indium and germanimn from their oxides is similar to that of vanadium. The melting temperature of indium oxide (ln203) is 2183 K. Decomposition of In203 is also endothermic, although energy consumption here is less than in the case of the direct reduction of vanadium ... 

Germanium oxide (Ge02) is characterized by a melting temperature of 1359 K, which is lower than that of indium oxide. It is characterized by a relatively low melting enthalpy A/fmeit = 0-22 eV/mol. Direct thermal plasma decomposition of Ge02 can be described as... 

Measurements at different heating rates may lead to different amounts of instrument-lag, i.e., the temperature marked on the DSC trace can only be compared to a calibration of equal heating rate and baseline deflection. A simple lag correction makes use of the slope of the indium melting peak when plotted vs. sample temperature as a correction to vertical lines on the temperature axis, hi some commercial DSCs this lag correction is included in the analysis program. It must be considered, however, that different samples have different thermal conductivities and thermal resistances so that different lags are produced as shown, for example, in Fig. 4.94, for an analysis with TMDSC. 

The degree of crystallinity x and the melting temperature of crystallites of each component in the blend were determined by DSC measurements performed on a differential scanning microcalorimeter DSM-lOmA operated at a temperature scan rate of 8°C/min [14], The temperature scale was gauged by Indium = 156.6 C, zl//= 28.44 J/g). 

Figure 3.1 Melting temperature of indium, sandwiched between polyethylene films, as a function of the distance (x) from the base of the sample vessel to the indium sample and as a function of heating rate...

Melting temperatures of different materials are identified as different portions of the thermal curve. During calibration the melting temperature of the calibration reference materials (usually a pure metal such as indium) is identified as the onset temperature of the melting peak (Fig. 4). 

Figure 4 Thermal curve of indium melting with a peak area calculation including the onset temperature and peak temperature. 

Now reassemble the clean DSC and run the indium sample again. Sometimes cleaning the DSC is all that is required to return the instrument to working order. Check the indium onset temperature of melting against the expected values and determine if the DSC still needs recalibration. 

After the run is over, calculate the melting temperature of water. This is easily done by calculating the peak temperature and including the onset temperature. In Fig. 4, an indium melt, observe that the limits of the calculation are set on the flat portion of the baseline before and after the melting peak. Use the onset temperature as the melting point of water. 

After baseline calibration is performed, heat flow calibration is done by melting a known quantity of a material with a well-known heat of fusion. Indium is the most often used standard. Indium is placed in the sample pan and scanned against an empty reference pan. The area of the melting peak is related to the known enthalpy of fusion by a calibration factor known as the celt constant. This procedure also calibrates the temperature axis from the known melting temperature of indium. Temperature calibration should also be performed over a wider temperature range, by measuring the melting points of several well-known standards. 

Regarding indium-based alloys the stoichiometry of the compound with the highest melting temperature varies in the lanthanide series the lanthanide content of this compound increases with atomic number. From this point of view thorium has a similar behavior to the light lanthanides. A more remarkable similarity between the lanthanide and... 

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