Thermal Transformation of a Synthetic Analogue of Insizwaite PtBi2 on Air

High-temperature transformation of β-PtBi2, a synthetic analogue of insizwaite, was studied under oxidizing conditions (on air). The behavior of the sample upon heating up to 660°C and cooling was studied by differential thermal analysis (DTA) and high-temperature X-ray powder diffraction. It was shown that polymorphic transitions of β-PtBi2 into high-temperature γ- and δ-polymorphs do not occur under thermal treatment in the oxidizing conditions (on air). The DTA curve shows two exothermic peaks at 318 and 620°C. The total weight change in the temperature range studied is +10.5