| Abstract Scope |
There are four main varieties of phase diagrams today: 1) Temperature–Pressure; 2) Temperature–Composition; 3) Ellingham (T, μO2); and 4) Pourbaix diagrams (pH, Redox potential). However, these 2D phase diagrams do not account for many other forms of thermodynamic work that may be operative in extreme environments—including surface, elastic, electromagnetic and electrochemical work. In such cases, it would be better to analyze materials stability on new varieties of phase diagrams that have these thermodynamic variables on the axes. Here, I will describe a geometric process to ‘lift’ 2D phase diagrams into higher dimensions, exposing these typically hidden forms of thermodynamic work on the axes. By properly accounting for these additional thermodynamic variables, we can reconcile many surprising experimental observations of “non-equilibrium” phases in extreme environments—which in fact may be the equilibrium phase under other various forms of applied work. |