Orbital-State-Mediated Phase-Control of Manganites

抄録

Using the epitaxial strain, the magnetic and electronic phases can be controlled for thin films of the manganites, La_1-xSr_xMnO₃, grown on perovskite substrates with various lattice parameters. The strain-induced orbital-ordering (disordering) via coupling with the cooperative Jahn-Teller distortion produces different spin-structures, such as ferromagnetic, layer-type or chain-type antiferromagnetic states, and hence different magnetoelectronic characteristics. The spin-orbital phase diagram for La_1-xSr_xMnO₃ films has been obtained in the plane of strain-field (c/a ratio) vs doping x, which can be quantitatively reproduced by the density-functional electronic-calculation.