Enhanced conduction and ferromagnetic order at (100)-type twin walls in La_sub0.7sub_Sr_sub0.3sub_Mn_subO3sub_ thin films
Lluís Balcells, Markos Paradinas, Núria Baguès, Neus Domingo, Roberto Moreno, Regina Galceran, Michael Walls, José Santiso, Zorica Konstantinovic, Alberto Pomar, Marie-Jo Casanove, Carmen Ocal, Benjamín Martínez, and Felip Sandiumenge;
Phys. Rev. B 92, 075111 – Published 7 August 2015
There is increasing evidence supporting the strong potential of twin walls in ferroic materials as distinct, spatially tunable, functional elements in future electronic devices. Here, we report an increase of about one order of magnitude in conductivity and more robust magnetic interactions at (100)-type twin walls in La0.7Sr0.3MnO3 thin films. The nature and microscopic origin of such distinctive behavior is investigated by combining conductive, magnetic, and force modulation scanning force microscopies with transmission electron microscopy techniques. Our analyses indicate that the observed behavior is due to a severe compressive strained state within an ∼1nm slab of material centered at the twin walls, promoting stronger Mn 3d−O2p orbital overlapping leading to a broader bandwidth and enhanced magnetic interactions.