Hülsen, Björn; Scheffler, Matthias; Kratzer, Peter:

Structural Stability and Magnetic and Electronic Properties of Co_2MnSi(001)/MgO Heterostructures: A Density-Functional Theory Study

In: Physical Review Letters, Jg. 103 (2009), S. 046802/1-4
Zeitschriftenaufsatz / Fach: Physik
A computational study of the epitaxial Co_2MnSi(001)/MgO(001) interface relevant to tunneling magnetoresistive devices is presented. Employing ab initio atomistic thermodynamics, we show that the Co or MnSi planes of bulk-terminated Co_2MnSi form stable interfaces, while pure Si or pure Mn termination requires nonequilibrium conditions. Except for the pure Mn interface, the half-metallic property of bulk Co_2MnSi is disrupted by interface bands. Even so, at homogeneous Mn or Co interfaces these bands contribute little to the minority-spin conductance through an MgO barrier, and hence such terminations could perform strongly in tunneling magnetoresistive devices.