First-principles calculations on magnetic properties of interface-rippled Co/α-Al2O3Co

Chiho Kim, Yong-Chae Chung

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The effects of the interface fluctuations on the magnetic properties of a Coα- Al2 O3 Co magnetic tunnel junction were intensively investigated using first-principles calculations. Hybridization of Co-3d and O-2p orbitals resulted in the covalent bonds between Co and three O atoms at the interface of Co(111)α- Al2 O3 (0001) and, subsequently, interfacial Co atoms became undulated as much as 34.6% of the interlayer distance measured in the z direction. The magnetic moment of Co atoms at the rippled interface was enhanced to 1.95 μB, while the value of the other ferromagnetic Co atoms remained unchanged. Significantly induced minority-spin density of states at the Fermi energy of the Co-interface atoms led to a highly negative spin polarization, -52.0%, at the junction interface. Interestingly, the spin polarization value for the barrier layer was in the range of -6.3%-59.2%.

Original languageEnglish
Article number132512
JournalApplied Physics Letters
Volume88
Issue number13
DOIs
StatePublished - 2006 Apr 11

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magnetic properties
atoms
covalent bonds
polarization
minorities
barrier layers
tunnel junctions
interlayers
magnetic moments
orbitals
energy

Cite this

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title = "First-principles calculations on magnetic properties of interface-rippled Co/α-Al2O3Co",
abstract = "The effects of the interface fluctuations on the magnetic properties of a Coα- Al2 O3 Co magnetic tunnel junction were intensively investigated using first-principles calculations. Hybridization of Co-3d and O-2p orbitals resulted in the covalent bonds between Co and three O atoms at the interface of Co(111)α- Al2 O3 (0001) and, subsequently, interfacial Co atoms became undulated as much as 34.6{\%} of the interlayer distance measured in the z direction. The magnetic moment of Co atoms at the rippled interface was enhanced to 1.95 μB, while the value of the other ferromagnetic Co atoms remained unchanged. Significantly induced minority-spin density of states at the Fermi energy of the Co-interface atoms led to a highly negative spin polarization, -52.0{\%}, at the junction interface. Interestingly, the spin polarization value for the barrier layer was in the range of -6.3{\%}-59.2{\%}.",
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First-principles calculations on magnetic properties of interface-rippled Co/α-Al2O3Co. / Kim, Chiho; Chung, Yong-Chae.

In: Applied Physics Letters, Vol. 88, No. 13, 132512, 11.04.2006.

Research output: Contribution to journalArticle

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AB - The effects of the interface fluctuations on the magnetic properties of a Coα- Al2 O3 Co magnetic tunnel junction were intensively investigated using first-principles calculations. Hybridization of Co-3d and O-2p orbitals resulted in the covalent bonds between Co and three O atoms at the interface of Co(111)α- Al2 O3 (0001) and, subsequently, interfacial Co atoms became undulated as much as 34.6% of the interlayer distance measured in the z direction. The magnetic moment of Co atoms at the rippled interface was enhanced to 1.95 μB, while the value of the other ferromagnetic Co atoms remained unchanged. Significantly induced minority-spin density of states at the Fermi energy of the Co-interface atoms led to a highly negative spin polarization, -52.0%, at the junction interface. Interestingly, the spin polarization value for the barrier layer was in the range of -6.3%-59.2%.

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