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Electronic and magnetic properties of SnO2/CrO2 thin superlattices.

Borges PD, Scolfaro LM, Leite Alves HW, da Silva EF, Assali LV - Nanoscale Res Lett (2011)

Bottom Line: In this article, using first-principles electronic structure calculations within the spin density functional theory, alternated magnetic and non-magnetic layers of rutile-CrO2 and rutile-SnO2 respectively, in a (CrO2)n(SnO2)n superlattice (SL) configuration, with n being the number of monolayers which are considered equal to 1, 2, ..., 10 are studied.A half-metallic behavior is observed for the (CrO2)n(SnO2)n SLs for all values of n.The ground state is found to be FM with a magnetic moment of 2 μB per chromium atom, and this result does not depend on the number of monolayers n.

View Article: PubMed Central - HTML - PubMed

Affiliation: Instituto de Física, Universidade de São Paulo, CP 66318, São Paulo, SP, 05315-970, Brazil. pdborges@gmail.com.

ABSTRACT
In this article, using first-principles electronic structure calculations within the spin density functional theory, alternated magnetic and non-magnetic layers of rutile-CrO2 and rutile-SnO2 respectively, in a (CrO2)n(SnO2)n superlattice (SL) configuration, with n being the number of monolayers which are considered equal to 1, 2, ..., 10 are studied. A half-metallic behavior is observed for the (CrO2)n(SnO2)n SLs for all values of n. The ground state is found to be FM with a magnetic moment of 2 μB per chromium atom, and this result does not depend on the number of monolayers n. As the FM rutile-CrO2 is unstable at ambient temperature, and known to be stabilized when on top of SnO2, the authors suggest that (CrO2)n(SnO2)n SLs may be applied to spintronic technologies since they provide efficient spin-polarized carriers.

No MeSH data available.


The supercell model and total energies for the systems. (a) Supercell used to study the (SnO2)1(CrO2)1 SL, and (b) Total energies for the non-magnetic (NM) and anti-ferromagnetic (AFM) states relative to the ferromagnetic (FM) state. The dashed lines connecting the points are to guide the eyes.
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Figure 1: The supercell model and total energies for the systems. (a) Supercell used to study the (SnO2)1(CrO2)1 SL, and (b) Total energies for the non-magnetic (NM) and anti-ferromagnetic (AFM) states relative to the ferromagnetic (FM) state. The dashed lines connecting the points are to guide the eyes.

Mentions: All the calculations were based on the spin density functional theory. The Projector-Augmented Wave method implemented in the Vienna Ab-initio Simulation Package (VASP-PAW) [5,6] was employed in this study, and for the exchange-correlation potential, the generalized gradient approximation and the Perdew, Burke, and Ernzerhof (GGA-PBE) approach was used [7]. The valence electronic distribution for the PAWs representing the atoms were Sn-- 4d10 5s2 5p2, Cr-- 3d5 5s1, and O-2s2 2p4. Scalar relativistic effects were included. For simulation of the one monolayer (CrO2)1(SnO2)1 SL, a supercell with 12 atoms (2Sn, 2Cr, and 8O) in the rutile structure as shown in Figure 1a was used. For this case, a 4 × 4 × 3 mesh of Monkhorst-Pack k-points was used for integration in the SL BZ. All the calculations were done with a 490 eV energy cutoff in the plane-wave expansions.


Electronic and magnetic properties of SnO2/CrO2 thin superlattices.

Borges PD, Scolfaro LM, Leite Alves HW, da Silva EF, Assali LV - Nanoscale Res Lett (2011)

The supercell model and total energies for the systems. (a) Supercell used to study the (SnO2)1(CrO2)1 SL, and (b) Total energies for the non-magnetic (NM) and anti-ferromagnetic (AFM) states relative to the ferromagnetic (FM) state. The dashed lines connecting the points are to guide the eyes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211196&req=5

Figure 1: The supercell model and total energies for the systems. (a) Supercell used to study the (SnO2)1(CrO2)1 SL, and (b) Total energies for the non-magnetic (NM) and anti-ferromagnetic (AFM) states relative to the ferromagnetic (FM) state. The dashed lines connecting the points are to guide the eyes.
Mentions: All the calculations were based on the spin density functional theory. The Projector-Augmented Wave method implemented in the Vienna Ab-initio Simulation Package (VASP-PAW) [5,6] was employed in this study, and for the exchange-correlation potential, the generalized gradient approximation and the Perdew, Burke, and Ernzerhof (GGA-PBE) approach was used [7]. The valence electronic distribution for the PAWs representing the atoms were Sn-- 4d10 5s2 5p2, Cr-- 3d5 5s1, and O-2s2 2p4. Scalar relativistic effects were included. For simulation of the one monolayer (CrO2)1(SnO2)1 SL, a supercell with 12 atoms (2Sn, 2Cr, and 8O) in the rutile structure as shown in Figure 1a was used. For this case, a 4 × 4 × 3 mesh of Monkhorst-Pack k-points was used for integration in the SL BZ. All the calculations were done with a 490 eV energy cutoff in the plane-wave expansions.

Bottom Line: In this article, using first-principles electronic structure calculations within the spin density functional theory, alternated magnetic and non-magnetic layers of rutile-CrO2 and rutile-SnO2 respectively, in a (CrO2)n(SnO2)n superlattice (SL) configuration, with n being the number of monolayers which are considered equal to 1, 2, ..., 10 are studied.A half-metallic behavior is observed for the (CrO2)n(SnO2)n SLs for all values of n.The ground state is found to be FM with a magnetic moment of 2 μB per chromium atom, and this result does not depend on the number of monolayers n.

View Article: PubMed Central - HTML - PubMed

Affiliation: Instituto de Física, Universidade de São Paulo, CP 66318, São Paulo, SP, 05315-970, Brazil. pdborges@gmail.com.

ABSTRACT
In this article, using first-principles electronic structure calculations within the spin density functional theory, alternated magnetic and non-magnetic layers of rutile-CrO2 and rutile-SnO2 respectively, in a (CrO2)n(SnO2)n superlattice (SL) configuration, with n being the number of monolayers which are considered equal to 1, 2, ..., 10 are studied. A half-metallic behavior is observed for the (CrO2)n(SnO2)n SLs for all values of n. The ground state is found to be FM with a magnetic moment of 2 μB per chromium atom, and this result does not depend on the number of monolayers n. As the FM rutile-CrO2 is unstable at ambient temperature, and known to be stabilized when on top of SnO2, the authors suggest that (CrO2)n(SnO2)n SLs may be applied to spintronic technologies since they provide efficient spin-polarized carriers.

No MeSH data available.