Atomic and Electronic Structure of CoFeB/MgO Interface from First Principles

Authors

John D. Burton, University of Nebraska-LincolnFollow
Sitaram S. Jaswal, University of Nebraska-LincolnFollow
Evgeny Y. Tsymbal, University of Nebraska-LincolnFollow
O. G. Heinonen, Seagate Technology, Bloomington, MN

Date of this Version

10-2006

Comments

Published in Applied Physics Letters 89, 142507 (2006); DOI: 10.1063/1.2360189 Copyright ©2006 The American Physical Society. Used by permission. http://link.aip.org/link/?APPLAB/89/142507/1

Abstract

First-principles calculations of the atomic and electronic structure of crystalline CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) are performed to understand the effect of B on spin-dependent transport in these junctions. The authors find that it is energetically favorable for B atoms to reside at the crystalline CoFeB/MgO interface rather than remain in the bulk of the crystalline CoFeB electrode. The presence of B at the interfaces is detrimental to tunneling magnetoresistance (TMR) because it significantly suppresses the majority-channel conductance through states of symmetry. Preventing B segregation to the interfaces during annealing should result in an enhanced TMR in CoFeB/MgO/CoFeB MTJs.