SYNTHESIS OF THE NEW COMPOUND CAFE(CO3)2 AND EXPERIMENTAL CONSTRAINTS ON THE (CA,FE)CO3 JOIN

摘要: Synthesis of the new (disordered) compound CaFe(CO3)2 has been achieved with use Fe-substituted CaCO3(Cc ss) + Ca-substituted FeCO3(Sid as starting materials, and high CO2 pressures. High pressure (20–30 kbar) is needed to stabilize FeCO3 sufficiently temperatures for disordered form. Experiments provide reversed compositions coexisting phases in CaFe join locate solvus temperature CaFe(C)3)2 between 815 845°C at 30 kbars. Calculated phase relations predict that stability ordered limited T < ∼450°C by breakdown Cc ss Sid ss. A comparison unit-cell volume measured vs. estimated suggests increasing stabilizes phase.