Study on the structural and magnetic properties of Ru1−xMoxSr2GdCu2O8±z system

The structural and magnetic properties of Ru_1-xMo_xSr₂GdCu₂O₈ with 0.0 ≤ x ≤ 0.50 were investigated through Mo substitution in the Ru sites. Samples were synthesized by solid-state reaction at ambient pressure at temperature between 960 °C and 1060 °C. X-ray diffraction results indicate that the partial substitution of Ru by Mo within the studied level of doping takes place isostructurally in a tetragonal structure (space group P4/mmm) with a solubility up to x = 0.50. Rietlveld- refinement analysis indicates that the Cu-O(2) and Ru-O(3) bond lengths increase with Mo content, while the Cu-O(1) and Ru-O(1) bond lengths, as well as Cu-O(1)-Ru bond angles decrease with increasing x with a minimum at approximately x = 0.30, and then increase for x > 0.30 resulting in inverse bell-type curves. Results of the DC magnetic susceptibility measurements on samples indicate that all samples exhibit ferromagnetic ordering, with T^Curie values depend on Mo content with a dependence that seems to be similar to Cu-O(1)-Ru bond angle. These results suggest a relationship between the structural and magnetic properties in the Ru_1-xMo_xSr₂GdCu₂O₈ system.