Double exchange-driven spin pairing at the (001) surface of manganites

Abstract

The (001) surface of La_{1-x}Ca_xMnO_3 system in various magnetic orderings is studied by first principle calculations. A general occurrence is that z^2 dangling bond charge -- which is ``invisible'' in the formal valence picture -- is promoted to the bulk gap/Fermi level region. This drives a double-exchange-like process that serves to align the surface Mn spin with its subsurface neighbor, regardless of the bulk magnetic order. For heavy doping, the locally ``ferromagnetic'' coupling is very strong and the moment enhanced by as much as 30% over the bulk value.

6 pages, 4 figures

References in corpus (1)

• Magnetic reconstruction at (001) CaMnO${}_3$ surface

Cited by in corpus (11)

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• Exchange interactions of CaMnO3 in the bulk and at the surface
• Surface antiferromagnetism and incipient metal-insulator transition in strained manganite films
• Strain induced magnetic transition in CaMnO${}_3$ ultra thin films
• Magnetic transition and spin-polarized two-dimensional electron gas controlled by polarization switching in strained CaMnO${}_3$/BaTiO${}_3$ slabs
• Role of symmetry mismatch, charge transfer and low dimensionality in the magnetic order of CaMnO${}_3$/SrTiO${}_3$ ultrathin heterostructures