The Oxidation of the Platinum Metals

Abstract

On gentle heating in air or in oxygen all six of the platinum metals develop thin tarnish films, visible or invisible, on their surfaces. On exceeding individual critical temperatures these films disappear, exposing clean metal, the change having the characteristics of a low-energy phase transformation. The mechanisms involved are examined in this survey and their effects on the stability, strength and surface reactivity of the platinum metals and their alloys are discussed.