Epitaxial integration of the highly spin-polarized ferromagnetic semiconductor EuO with silicon and GaN.
Doped EuO is an attractive material for the fabrication of proof-of-concept spintronic devices. Yet for decades its use has been hindered by its instability in air and the difficulty of preparing and patterning high-quality thin films. Here, we establish EuO as the pre-eminent material for the direct integration of a carrier-concentration-matched half-metal with the long-spin-lifetime semiconductors silicon and GaN, using methods that transcend these difficulties. Andreev reflection measurements reveal that the spin polarization in doped epitaxial EuO films exceeds 90%, demonstrating that EuO is a half-metal even when highly doped. Furthermore, EuO is epitaxially integrated with silicon and GaN. These results demonstrate the high potential of EuO for spintronic devices.
Schmehl
Andreas
A
Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802-5005, USA.
Vaithyanathan
Venu
V
Herrnberger
Alexander
A
Thiel
Stefan
S
Richter
Christoph
C
Liberati
Marco
M
Heeg
Tassilo
T
Röckerath
Martin
M
Kourkoutis
Lena Fitting
LF
Mühlbauer
Sebastian
S
Böni
Peter
P
Muller
David A
DA
Barash
Yuri
Y
Schubert
Jürgen
J
Idzerda
Yves
Y
Mannhart
Jochen
J
Schlom
Darrell G
DG
D003198:Computer Simulation; D018360:Crystallography, X-Ray; D005063:Europium / Q000737:chemistry*; D005708:Gallium / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D010087:Oxides / Q000737:chemistry*; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry*
D010087:Oxides; C473348:gallium nitride; D005063:Europium; D005708:Gallium; D012825:Silicon