Neues über Oxoferrate(III). I. Zur Kenntnis von Li5FeO4 [1] Mit einer Notiz über Mischkristalle Na5Fe1−xGaxO4

News on Oxoferrates(III). I. On Li₅FeO₄ (with a Remark on Na₅Fe_1?xGa_xO₄ Solid Solutions) For the first time transparent dark yellow single crystals of Li₅FeO₄, corresponding to Li₅□₂FeO₄ an ordered variant of the Na₂O-type of structure, are prepared by mixtures of Li₂O and α-NaFeO₂ with Li:Na:Fe = 6:1:1, sealed Ag-cylinders, 700°C, 16 d]. Li₅FeO₄ is isostructural with Li₅GaO₄: a = 921.8(1), b = 921.3(1), c = 915.9(1) pm, Z = 8 space group: Pbca, 4-circlediffractometer data, 2525 I₀ (hkl), R = 9.58% and R_w = 5.85%, d_pyk = 2.60 and d_x = 2.64 gcm^?3, parameters see text]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated and discussed. The magnetic properties are measured in the temperature range of 3.9–251.3 K.