Cadmium addition to vacancy doped lanthanum manganites: from metallic to insulator behaviour

Abstract A study of transport and magnetic properties of Cd manganites in bulk ceramic and thin films is presented. Although Cd and Ca ions have the same valence and similar cation sizes, their incorporation into vacancy doped La manganites induces different properties. Both series are ferromagnetic with the usual peak in magnetoresistance close to T c , but Cd reduces T c severely (from 250 K down to 148 K, for 25% Cd) and promotes insulator-like behaviour. Similar effects are found in thin films and substrate induced strain effects (LaAlO 3 and SrTiO 3 ) are evidenced on the electrical properties.