TY - JOUR
T1 - Effects of interfacial noncollinear magnetic structures on spin-dependent conductance in Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions
T2 - A first-principles study
AU - Miura, Yoshio
AU - Abe, Kazutaka
AU - Shirai, Masafumi
PY - 2011/6/13
Y1 - 2011/6/13
N2 - We investigate the effects of spin-flip scattering on tunneling magnetoresistance (TMR) in magnetic tunnel junctions (MTJs) with half-metallic Co2MnSi (CMS) and MgO on the basis of the first-principles calculations. We found that noncollinear magnetic structures of interfacial Co spin moments resulting from the thermal fluctuations cause spin-flip scattering, leading to a significant reduction of the TMR. Interface states originating from a projection of the majority-spin Δ1 states of CMS in the minority-spin half-metallic gap because of the interfacial noncollinear magnetic structures play an important role in the spin-flip process. From these results, together with an estimated interfacial exchange stiffness constant, we conclude that the TMR ratio at room temperature in MTJs with half-metallic Co-based full-Heusler alloys can be attributed to the spin-flip scattering by the interfacial noncollinear magnetic structures as a result of the thermal fluctuation.
AB - We investigate the effects of spin-flip scattering on tunneling magnetoresistance (TMR) in magnetic tunnel junctions (MTJs) with half-metallic Co2MnSi (CMS) and MgO on the basis of the first-principles calculations. We found that noncollinear magnetic structures of interfacial Co spin moments resulting from the thermal fluctuations cause spin-flip scattering, leading to a significant reduction of the TMR. Interface states originating from a projection of the majority-spin Δ1 states of CMS in the minority-spin half-metallic gap because of the interfacial noncollinear magnetic structures play an important role in the spin-flip process. From these results, together with an estimated interfacial exchange stiffness constant, we conclude that the TMR ratio at room temperature in MTJs with half-metallic Co-based full-Heusler alloys can be attributed to the spin-flip scattering by the interfacial noncollinear magnetic structures as a result of the thermal fluctuation.
UR - http://www.scopus.com/inward/record.url?scp=79961133999&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79961133999&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.83.214411
DO - 10.1103/PhysRevB.83.214411
M3 - Article
AN - SCOPUS:79961133999
VL - 83
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 21
M1 - 214411
ER -