D0 ferromagnetic interface between nonmagnetic perovskites

R. Oja; M. Tyunina; L. Yao; T. Pinomaa; T. Kocourek; A. Dejneka; O. Stupakov; M. Jelinek; V. Trepakov; S. Van Dijken; R. M. Nieminen

doi:10.1103/PhysRevLett.109.127207

D0 ferromagnetic interface between nonmagnetic perovskites

R. Oja^*, M. Tyunina, L. Yao, T. Pinomaa, T. Kocourek, A. Dejneka, O. Stupakov, M. Jelinek, V. Trepakov, S. Van Dijken, R. M. Nieminen

^*Corresponding author for this work

Not published at VTT

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48 Citations (Scopus)

Abstract

We use computational and experimental methods to study d0 ferromagnetism at a charge-imbalanced interface between two perovskites. In SrTiO ₃/KTaO ₃ superlattice calculations, the charge imbalance introduces holes in the SrTiO ₃ layer, inducing a d0 ferromagnetic half-metallic 2D hole gas at the interface oxygen 2p orbitals. The charge imbalance overrides doping by vacancies at realistic concentrations. Varying the constituent materials shows ferromagnetism to be a general property of hole-type d0 perovskite interfaces. Atomically sharp epitaxial d0 SrTiO ₃/KTaO ₃, SrTiO ₃/KNbO ₃, and SrTiO ₃/NaNbO ₃ interfaces are found to exhibit ferromagnetic hysteresis at room temperature. We suggest that the behavior is due to the high density of states and exchange coupling at the oxygen t _1g band in comparison with the more studied d band t _2g symmetry electron gas.

Original language	English
Article number	127207
Journal	Physical Review Letters
Volume	109
Issue number	12
DOIs	https://doi.org/10.1103/PhysRevLett.109.127207
Publication status	Published - Sept 2012
MoE publication type	A1 Journal article-refereed

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title = "D0 ferromagnetic interface between nonmagnetic perovskites",

abstract = "We use computational and experimental methods to study d0 ferromagnetism at a charge-imbalanced interface between two perovskites. In SrTiO 3/KTaO 3 superlattice calculations, the charge imbalance introduces holes in the SrTiO 3 layer, inducing a d0 ferromagnetic half-metallic 2D hole gas at the interface oxygen 2p orbitals. The charge imbalance overrides doping by vacancies at realistic concentrations. Varying the constituent materials shows ferromagnetism to be a general property of hole-type d0 perovskite interfaces. Atomically sharp epitaxial d0 SrTiO 3/KTaO 3, SrTiO 3/KNbO 3, and SrTiO 3/NaNbO 3 interfaces are found to exhibit ferromagnetic hysteresis at room temperature. We suggest that the behavior is due to the high density of states and exchange coupling at the oxygen t 1g band in comparison with the more studied d band t 2g symmetry electron gas.",

author = "R. Oja and M. Tyunina and L. Yao and T. Pinomaa and T. Kocourek and A. Dejneka and O. Stupakov and M. Jelinek and V. Trepakov and {Van Dijken}, S. and Nieminen, {R. M.}",

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doi = "10.1103/PhysRevLett.109.127207",

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T1 - D0 ferromagnetic interface between nonmagnetic perovskites

AU - Oja, R.

AU - Tyunina, M.

AU - Yao, L.

AU - Pinomaa, T.

AU - Kocourek, T.

AU - Dejneka, A.

AU - Stupakov, O.

AU - Jelinek, M.

AU - Trepakov, V.

AU - Van Dijken, S.

AU - Nieminen, R. M.

PY - 2012/9

Y1 - 2012/9

N2 - We use computational and experimental methods to study d0 ferromagnetism at a charge-imbalanced interface between two perovskites. In SrTiO 3/KTaO 3 superlattice calculations, the charge imbalance introduces holes in the SrTiO 3 layer, inducing a d0 ferromagnetic half-metallic 2D hole gas at the interface oxygen 2p orbitals. The charge imbalance overrides doping by vacancies at realistic concentrations. Varying the constituent materials shows ferromagnetism to be a general property of hole-type d0 perovskite interfaces. Atomically sharp epitaxial d0 SrTiO 3/KTaO 3, SrTiO 3/KNbO 3, and SrTiO 3/NaNbO 3 interfaces are found to exhibit ferromagnetic hysteresis at room temperature. We suggest that the behavior is due to the high density of states and exchange coupling at the oxygen t 1g band in comparison with the more studied d band t 2g symmetry electron gas.

AB - We use computational and experimental methods to study d0 ferromagnetism at a charge-imbalanced interface between two perovskites. In SrTiO 3/KTaO 3 superlattice calculations, the charge imbalance introduces holes in the SrTiO 3 layer, inducing a d0 ferromagnetic half-metallic 2D hole gas at the interface oxygen 2p orbitals. The charge imbalance overrides doping by vacancies at realistic concentrations. Varying the constituent materials shows ferromagnetism to be a general property of hole-type d0 perovskite interfaces. Atomically sharp epitaxial d0 SrTiO 3/KTaO 3, SrTiO 3/KNbO 3, and SrTiO 3/NaNbO 3 interfaces are found to exhibit ferromagnetic hysteresis at room temperature. We suggest that the behavior is due to the high density of states and exchange coupling at the oxygen t 1g band in comparison with the more studied d band t 2g symmetry electron gas.

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DO - 10.1103/PhysRevLett.109.127207

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SN - 0031-9007

VL - 109

JO - Physical Review Letters

JF - Physical Review Letters

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M1 - 127207

ER -

D0 ferromagnetic interface between nonmagnetic perovskites

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