Fig. 1: Calculation-guided design of metastable ɛ-Fe2C.
From: Potassium-stabilized metastable carbides and chalcogenides via surface chemical potential modulation
a Schematic of the classical strategy for synthesizing metastable species and our proposed K+-modified strategy by modulating the chemical potential μ and reaction equilibrium. IP initial phase, R reactants, MP metastable phase, SP stable phase. b Schematic of the phase diagram of the Fe‒C system. c DFT calculation of the bulk phase evolution (∆μC), bulk over the Fe3O4 and Fe2N precursors. d Free-energy diagram of the construction process over Fe2N and K-Fe2N under CO2 and H2 atmospheres. Purple: K, red: O, blue: N, pink: H, light brown: C, and brown: Fe. Visuals were produced with VESTA50.
