Iridium ionization energy

The increased ionization energies of the heavier transition metals should not be unexpected by anyone who has had a modicum of laboratory experience with any of these elements. Although none of the coinage metals is very reactive, gold has a well-deserved reputation for being less reactive than copper or silver iron, cobalt, and nickel rust and corrode, but osmium, iridium, and platinum are noble and unreactive and therefore are used in jewelry platinum wires are the material of choice for flame tests without contamination and one generates hydrogen with zinc and simple acids, not with mercury. 

Surface Ionization Sources. In this system, a low ionization potential atom (e.g. caesium) is adsorbed on a high work function metal (e.g. iridium). The temperature is raised so that the rate of desorption exceeds the rate of arrival of the atoms at the surface, and the Cs is then desorped as ions with very small energy spread (< 1 eY). The spot size - current characteristics of these sources lie between liquid metal and plasma discharge sources. 

The wide-range radiolysis source shown schematically in Figure 1 consisted of three separate stainless steel compartments (A, B, C) in series, each with its own electron beam (designated hereafter as EB— e.g., EB-B means electrons beam in Compartment B). The energy and intensity of each EB emitted from a thoria-iridium filament could be varied independently by a versatile emission regulator (22) to suit the particular phase of the problem under study. The EB s were magnetically collimated to ensure localized ionization, and their intensities were usually about 10 fiA. 

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