Self-Organized Growth of Clustered Structures in La0.6-xNdxSr0.3Mn1.1O3-δ Doped Perovskites

Our results on the atomic order in La0.6-xNdxSr0.3Mn1.1O3-delta manganites with partial Nd substitution for La (x = 0-0.4) demonstrate that all of the materials consist of differently sized groups: microcrystalline groups with long-range atomic order, D = 300-600 angstrom in size; clustered groups with mesoscopic atomic order and D = 100-200 angstrom ; amorphous clustered groups with D = 20-30 angstrom ; and a disordered material with short-range atomic order, on a length scale of two or three interatomic distances (D similar to 10 ). It has been shown that, in the case of partial Nd substitution for La (x = 0.1-0.2) in the manganite, clusters 100-200 angstrom in size, as well as those of the rhombohedral phase 20-50 angstrom in size, initiate an FM -> AFM magnetic phase transition in the range 200-250 K. Neodymium substitution for half of the lanthanum (in La0.3Nd0.3Sr0.3Mn1.1O3-delta) has been found to result in the development of self-organization processes, with a reduction in cluster size fluctuations in the range Delta D approximate to +/- 50 angstrom in the orthorhombic ferromagnetic and rhombohedral antiferromagnetic phases.