Gallium transport

Below dris temperature, mainly GaCls transports gallium, but above dris temperature, the monochloride will begin to predominate. 

Photodetectors operate by carrier transport across a semiconductor junction. A wide variety of these photodiodes are available, such as Schottky diodes, phototransistors, and avalanche photodetectors. Typical photodetector materials are gallium arsenic phosphide and gallium phosphide, which are produced by MOCVD or MBE. 

In the transport of gallium arsenide by chlorine, there is a competition between the monochloride and the trichloride for the transport of gallium after arsenic has evaporated as the element or as a chloride. The probability... 

Gallium is non-essential, but on account of the similarity between Ga3+ and Fe3+ it binds to iron transport and storage proteins such as transferrin and ferritin. The radioactive isotope of gallium, 67Ga, concentrates to a large extent in many tumours and at sites of inflammation and infection, and since many tumours overexpress the transferrin receptor it can be used for tumour imaging. 

The composition of low-volatility two-component compounds in the Ga-Se system as controlled using chemical transport reactions has been studied (Zavrazhnov et al. 2003). For long-term heat treatment of a low-volatility phase in the presence of a transport agent, the annealed phase composition was found to be determined only by the temperature and the nature of the sample. In the case of a two-temperature anneal of gallium selenides with added iodine, the sample composition ranges are presented as a function of the cold and hot zones temperatures. A scheme of their experimental arrangement is shown in Fig. 6.14. 

In one method, arsenic(III) chloride (AsCf, boiling temperature 376 K) is used to transport gallium vapour to the reaction site where gallium arsenide is deposited in layers. The reaction involved is ... 

As mentioned above, silicon has been found to be a very valuable material with which to study the influence of the oxide layer. This is because the oxide layer on silicon is an excellent insulator, i.e. there is no problem with carrier transport through impurity bands. This makes the interpretation much simpler with silicon than it would be, for example, with the oxide on gallium arsenide (4) where the oxide seems to have sufficient conductance to complicate the interpretation. 

Serum transferrin is normally only about 30% saturated with iron. This explains why it has a relatively high capacity for binding other metals and so is implicated in the transport of 67Ga,1139 which is used as an imaging agent for various soft tissue tumours and inflammatory abscesses.1140 Transferrin also facilitates movement of gallium across tumour cell membranes.1141... 

In the last reaction, the starting reactants would be AsC13, gallium and H2. Table 1 lists several examples of chemical transport systems. 

A major objective of these CMBs was to determine primary and secondary contributions from coal-fired plants. Arsenic and Se are often used as "markers" for primary emissions from coal-fired plants (10), but Table II shows that substantial amounts of these elements are associated with regional sulfate, most of which results from transport from distant coal-fired plants. The regional sulfate component was based largely on FA of fine particles collected in Shenandoah Valley (4), which mainly represents material transported into the area from the west. As previously discussed (11), broadly similar components can be constructed from data of Thurston and Spengler (6), Pierson et al. (12), and Rahn and Lowenthal (13). At present, we don t know if this component is appropriate for samples collected within the ORV. Also, industrial sources such as copper plants and iron and steel mills interfere with some elements that might otherwise be good markers for coal combustion. Gallium shows... 

---