The thermodynamic properties were reviewed by the author in 1995. A new assessment of the enthalpy of fusion has led to a revision of the thermodynamic properties of the liquid phase and although the enthalpy of sublimation at 298.15 K is retained as 377 ± 4 kJ mol–1 the normal boiling point is revised to 3272 K at one atmosphere pressure.
Definitive equations are suggested to represent the variation with temperature of the densities and molar volumes of the liquid platinum group metals whilst the previously unknown initial slopes of the melting curves for iridium, rhodium and ruthenium are estimated. 1. Introduction Paradis et al. (1) summarised determinations of the densities of the liquid platinum group metals but a...
The properties and glass-forming ability (GFA) of platinum- and palladium-based bulk metallic glasses (BMGs) for jewellery were introduced in Part I of this two-part review (1). Here, we will describe methods for their processing, tarnishing and corrosion resistance and consider their prospects and future developments.
Barring the presence of significant amounts of impurities, an important cause of thermoelectric inhomogeneity and therefore calibration drift of platinum-rhodium thermocouples at high temperatures is the vaporisation and transport of the oxides of Pt and Rh, which causes local changes in wire composition. By examining the vapour pressures of Pt and Rh oxides and their temperature dependence, it is shown that at a given temperature there is an optimal wire composition at which evaporation of the oxides has no effect on the wire composition, provided the vapour does not leave the vicinity of the wire. This may also have applications for Pt-Rh heater elements.