K2NiF4 TYPE OXIDES : THE COMPOUNDS La2-xSrxNiO4-y : CRYSTAL CHEMISTRY AND ELECTRICAL PROPERTIES

Abstract

The substitution of lanthanum for strontium has been studied in La2NiO4. A family of mixed oxides with the formulation La2-xSrxNiO4-y has been air obtained with a wide homogeneity range (0 ≤ x ≤ 1.2). Structuraland electrical properties are discussed from X ray diffraction results and electrical conductivity measurements. We show up especially a strong relationship between the geometrical distortion of the Ni octahedra and the electrical properties (σ ~ 100 (Ω.cm)-1 for 0.8 ≤ x ≤ 1)