Sc-doping and A-site deficiency effects on the structure and magnetic properties of La0.7Sr0.3-yMn1-xScxO3 lanthanum manganites

A study of the single-phase La0.7Sr0.3-yMn1-xScxO3 A (=La,Sr)-site deficiency and B (=Mn,Sc)-site substituted manganites is presented. All the compositions belong to the R3-bar c rhombohedral space group. Three groups of samples, G1 (y=0; x=0-0.05), G2 (x=0, y=0-0.03), and G3 (x=y=0-0.03) show the continuous change of structure parameters and decrease in Curie temperature, TC, with the Sc content or/and deficiency in A-position. The cell parameters and cell volume increase with x and y in G1 and G3 sample groups. The lattice c-parameter decreases while the a-parameter and cell volume increase with y in G2 sample group. The decrease in the TC in the G1 group is mostly caused by the destruction of eg electron pathway because of a difference in electron configuration of Mn3+ and Sc3+ ions, and partially by the lattice distortion because the larger Sc3+ ion than the Mn3+ ion