Mechanism of solid-state reaction between iridium and tantalum

Abstract The solid-state reaction between iridium and tantalum was studied in a wide temperature range. Two experimental approaches, namely, a hot pressing of the powder mixtures and a heat treatment of contact couples composed of iridium and tantalum foils were proposed. The phase and elemental composition, as well as the morphology of the products, were studied by a set of analytical techniques. It was stated that the reaction of metallic Ir and Ta leads to the formation of two layers of intermetallic products. The first layer has the variable elemental composition and consisted of the Ta3Ir, Ta2Ir3, and TaIr phases. The second layer is a TaIr3±x solid solution. The change in the width of each sublayer in dependence on the heat treatment temperature was determined.