Gases indium tube

Indium also has many of the characteristics that make Al and Ga very useful for such applications. Particularly important is its capacity to dissolve Si, Ge and several lanthanide and transition metals, producing highly reactive forms of the elements. Moreover In does not form binaries with Si and Ge and has a low-melting point. RNiGe2 compounds, for instance, were prepared from stoichiometric quantities of the components in fine powder mixed with a 10 fold quantity of In in alumina tubes. These, flame sealed in fused silica tubes, were slowly heated to 1000°C, held at this temperature for a few hours, ramped down to 850°C, held for an additional 4 days and finally cooled down to room temperature over the course of another 4 days. Compound isolation from the In excess was performed by centrifugation at 300°C through a coarse frit. Further purification was carried out by a 15-minute submersion and sonication in 6 M aqueous HC1 (Salvador et al. 2004). 

The reactions are carried out in a 200-mL tail-form beaker, with a tightly fitting rubber stopper through which the platinum electrode leads are inserted gas inlet and outlet tubes can be inserted as required. The cathode is a platinum wire carrying a 2 X 2 cm platinum sheet. The anode is a platinum wire onto which a shot of indium is beaten to form a 1 X 1 cm plate. The electrodes are placed 1-2 cm apart in the liquid phase, which is a mixture of organic solvents. 

Indium metal (0.85 g) is maintained at +15 V in a solution phase of 100 mLof 50 50 benzene-dimethyl sulfoxide (dmso). Benzene is purified as in Section A above dimethyl sulfoxide is dried over 4A molecular sieves before use. The cell is cooled in an ice bath throughout the experiment. Chlorine gas is bubbled slowly through the solution phase (about one bubble per second from a 2-mm tube) for 2 hours. At the end of this period, the solution is brown, and most of the indium has dissolved approximately 0.1 g of corroded material remains. 

The burner heads used in such cool flame emission studies are often simply quartz tubes. Figure 12 shows the burner system used by Arowolo and Cresser27 for automated gas-phase sulfide determination, for example. Other species determined by cool flame emission techniques include chloride, bromide, and iodide, which give intense emission in the presence of indium.29 The main application of cool flame emission techniques in environmental analysis is in speciation studies, for example for the separate determination of sulfite and sulfide, or as element-selective detectors in gas chromatography. 

The University of Illinois system (22) is also similar to the RCA system except that the growth tube is vertical and total H2 flow is 500-900 seem (standard cm3 min-1). A novel system of suspended indium boats (see Fig. 3) is used to ensure intimate contact of HC1 gas (with the metal sources). A metal surface area of only 14 cm2 is employed. A magnetic feedthrough is used to lift and rotate the substrate. 

Figure 1 Matrix apparatus as used in Nottingham (1) valve power supply, (2) helium pressure connections to compressor, (3) silicon diode and heater lead-through, (4) pump-out port, (5) gas inlet port, (6) cold station, (7) heater and thermocouple wires, (8) stainless steel tube, (9) silicon diode, (10) very cold station and heater sleeve, (11) cell, (12) photolysis and spectroscopic windows, for an experiment the cell is turned by 90° towards the windows, (13) vacuum shroud, (14) large half of cell, (15) small half of cell, (16) IR optical windows, (17) lead seal, (18) indium window seal, (19) circlip retainer groove, (20) bolt, (21) steel washer, (22) spring washer, (23) nut, (24) femal-femal union, (25) steel tubing, (26) to very cold station, (27) threaded copper stud, (28) threaded hole in large half of cell to receive stud, (29) indium joints, (30) circlip, which fits in groove and retains windows.

The system consists of a reservoir located above the upper plenum and subdivided into compartments. The liquid metal is stored in the reservoir, which is fitted with siphon tubes and bulbs. One end of the siphon is dipped into the liquid metal and the other opens into the inner gas gap multiple siphon tubes are employed. The bulb is located immediately downstream of the heat pipes and normally senses a temperature of 1173 K in case of a failure of the heat pipes, the coolant immediately senses a temperature of 1273 K. This would increase the pressure of the gas inside the bulb, cause the liquid metal to rise inside the siphon tube and ultimately, start the siphon. The liquid metal would then exit into the inner gas gap and fill the outer air gap through holes in the inner gas gap wall. The gas inside the gas gap would be pushed into a gas tank. A connector between the liquid metal and the gas tank would handle the decrease in pressure caused by the fall in level of the liquid metal in the reservoir, such that after some time, the pressure in the reservoir and the gas gaps would be equalized. Table XXIX-6 shows the calculated times taken to fill the gas gap after the start of the siphon. Indium has been assumed as the poured liquid metal. A schematic of this system is shown in Fig. XXIX-14. Return of the poured liquid metal to the reservoir would be accomplished by active means. 

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