Solid solutions La 1− xAg yMnO 3+ δ: evidence for silver doping, structure and properties

Abstract

Our experiments on the preparation of the composites of CMR manganites and metal silver have shown that in the case of La 1− x MnO 3+ δ the vacancies in the A-sublattice of the perovskite structure can be filled by Ag + ions under the soft conditions of the synthesis. Neutron diffraction refinement of La 0.8Ag 0.2MnO 3.00 clearly proves the silver doping in the A-sublattice. Depending on P(O 2)– T synthesis conditions the solid solutions with the broad stoichiometry range La 1− x Ag y MnO 3+ δ (0.3 ≥ x ≥ y) were prepared. We report here the evolution of the oxygen stoichiometry, the crystal structure as well as electro-physical properties in the series of the solid solutions. Curie temperature comes over a maximum exceeding the room temperature with the increase of silver content. La 1− x Ag y MnO 3+ δ solid solutions can be useful for the construction of the room temperature magnetic field sensors based on the magnetoresistance effect.