Influence of sodium doping on the electrical and magnetic properties of La0.90Li0.10MnO3 manganites

Monovalent perovskite manganites La0.90Li0.10−xNaxMnO3 were synthesized by using the solid-state reaction method. The crystal structure analysis presented that the samples are a single-phase rhombohedral (R3¯c) structure with no detectable impurity phases. Magnetic measurement showed a cusp at a certain temperature TC/F that gradually disappeared with adding the Na content. The samples undergo ferromagnetic-paramagnetic transition, accompanying the metal-semiconductor transition at Tms. There is irreversible on low field M (T)ZFC and M (T)FC curves which gradual decrease with increasing the Na doping. The resistivity values decreased and the Tms increased as doping of sodium increased. In addition, two-transition temperature Tms appeared just by adding the sodium. In short, the influence of partial substitution of lithium by sodium at A-site cation of lanthanum manganite on its physical properties was studied.