[1] Johannes Gutenberg Univ Mainz, Phys, Mainz, Germany
[2] Univ Tennessee, Knoxville, TN 37996 USA
[3] Univ Texas Austin, Austin, TX 78712 USA
[4] Texas A&M Univ, Phys, College Stn, TX 77843 USA
[5] Indiana Univ, Spintron, Bloomington, IN 47405 USA
[6] Univ Nottingham, Nottingham, England
[7] Acad Sci Czech Republ, Inst Phys, Dept Spintron & Nanoelect, Prague, Czech Republic
[8] Natl Tech Univ Ukraine KPI, Kiev, Ukraine
[9] Johannes Gutenberg Univ Mainz, INSPIRE Grp, Mainz, Germany