Influence of oxygen content on the magnetic properties of B-site deficient lanthanum manganites

The results of X-ray diffraction and magnetization measurements performed for LaMn0.94Ox (2.91 ≤ x ≤ 3.00) manganites have been presented. The solid solutions have been found to possess three different structural forms (orbitally ordered orthorhombic, orbitally disordered orthorhombic, and monoclinic ones), depending on the oxygen concentration. The transitions from an antiferromagnetic to an inhomogeneous ferromagnetic, and then to a spin-glass phase have been observed with increasing oxygen content. The experimental results have been discussed in the framework of the ionic distribution model adapted to the case of B-site deficient manganites.