Hyperfine fields at the Cd site in La0.67Cd0.25MnO3 CMR manganites

Although Cd and Ca ions have the same valence and cation size, their incorp oration into vacancy-doped La manganites induce different properties. While the incorporation of Ca leads to high Tc up to 250 K and induces a metalli c-like behaviour, the incorporation of Cd severely reduces Tc and promotes insulator-like behaviour. In this work, the Cd hyperfine fields have been m easured with the Perturbed Angular Correlations (PAC) technique after impla ntation and annealing of Cd-111m in La-Cd-MnO3 samples. The PAC results are compared with measurements of the resistivity and magnetization performed on the same samples. The mixed La and Mn site Cd occupancy is suggested as a possibility to explain the properties of the La-Cd-MnO3 system.