Effects of lattice modulation on magnetic properties of epitaxial ferromagnetic/paramagnetic manganite superlattices

摘要

Strained artificial superlattices of (La0.7Ba0.3)MnO3/LaNiO3 (LBMO/LNO) were formed on SrTiO3 (001) substrates by radio frequency magnetron sputtering. The result of (00L) crystal truncation rod intensity profiles reveals an enhancement of tetragonality of LBMO lattice in the designed superlattices due to the misfit strain at the hetero-interface. Absorption experiments give the evidence of the discrepancy among the in-plane nearest-neighbor Mn-O bond length of the LBMO/LNO superlattices with different modulation lengths; the oxidation state of Mn atoms for LBMO sublayers in a series of strained LBMO/LNO superlattices is independent of the thickness of LNO spacer. The strain in the superlattice structure contributes significantly to the suppression of Curie temperature of the LBMO/LNO superlattices. (c) 2006 Elsevier B.V. All rights reserved.