Slight La doping induced ferromagnetic clusters in layered La3-3xSr1+3xMn3O10 (x=1.00,0.99,0.95) -: art. no. 132403

The magnetic properties of the layered manganites La3-3xSr1+3xMn3O10 with x=1.00, 0.99, and 0.95 have been studied by dc and ac magnetization as well as specific heat measurements. For x=1.00, the magnetization shows a broad peak centered around 160 K, which is due to a short-range low-dimensional antiferromagnetic ordering. Below T-N=67 K where the anomaly of magnetic specific heat is observed, the system possibly develops into a long-range three-dimensional antiferromagnetic ordering. The anisotropic magnetic interactions between Mn ions are responsible for the temperature-dependent spin ordering. For x=0.99 and 0.95, the slight doping of La leads to significant changes in magnetic properties. The zero-field cooled and field cooled magnetization, ac susceptibility, as well as isothermal M-H curves suggest that La doping induces ferromagnetic clusters in the antiferromagnetic matrix. The shift of the specific heat peak indicates that the antiferromagnetic coupling in the matrix is weakened due to La doping.