Bismuth is a brittle metal which is silvery in color with a pink tinge. It is stable in air and water. Bismuth has poor thermal and electrical properties but finds applications in the manufacture of fusible alloys, a range of materials with low melting points which are suitable for various applications including solders and thermal fuses. Pure bismuth shows a high absorbtion of gamma rays which makes it useful as a filter or window for these particles, whilst at the same time permitting the passage of neutrons.
Bi exhibits thermal conductivity and this property allows it be used in various applications, such as thermoelectric conversion, devices exploiting large magneto-resistance and reference electrodes used to detect heavy metals. Another interesting property exhibited by Bi is the transformation of films of this semi-metal in to semiconductors at a critical thickness of approximately 30 nm. These films can be deposited by different techniques such as laser pulsed deposition, RF and DC sputtering and thermal evaporation. Moreover, it is important to note that different authors have reported that when coatings are deposited through physical vapor deposition (PVD) techniques the crystalline structure and morphology of the Bi coatings depend on the deposition parameters such as: the temperature of the substrate, the potential applied to the target, the ion beam energy and the rate at which energy is released when the films are deposited by ion beam bombardment. In DC sputtering, these parameters can be affected by applying positive pulses between the substrate and the target; this improves the film’s density and mechanical properties. For a detailed information you may check out the paper given in the link below:
You may give an order of bismuth sputtering targets from the link given on the table below.
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