Solid-phase equilibria in the system NiOMn2O3O2

摘要: Abstract A complete phase diagram is presented for the system NiOMn2O3O2 showing phases which can exist in air or pure oxygen at temperatures between 600 and 1200°C. Six are observed: rock-salt Ni1−sMns O ≤ s 0·025), an ordered Ni6MnO8, ilmenite Ni2−pMnpO3 (1 p 1·06), a cubic spinel Ni3−yMnyO4 (1·725 y 3·000), tetragonal (2·895 3·000) C-rare-earth-oxide α-Mn2O3 Mn2−zNizO3 (O z 0·230). Argument drawn to show that all except simple probably contain manganese +4 oxidation state.