Abstract:
While NdNiO3-δ prepared ordinarily is highly oxygen-deficient and exhibits a metal-insulator transition at low temperature, it has been possible to prepare nearly metallic NdNiO3-δ (δ = 0.05) by electrochemical oxidation. On progressive electrochemical oxidation, orthorhombic, insulating LaMnO3 transforms to a rhombohedral and then to a cubic structure. The last two phases are ferromagnetic and exhibit metal-insulator transitions.