Abstract
Recently, a high mobility quasi-two-dimensional
electron gas (q-2DEG) has been reported for the heterointerface between two insulating
and nonmagnetic oxides of spinel γ-Al2O3 and perovskite
SrTiO3 (STO). Herein, we fabricated the epitaxial heterostructure
with Al-based magnetic spinel oxide MAl2O4
(M = Fe, Co, Ni) on perovskite STO.
Remarkably, all the MAl2O4
(M = Fe, Co, Ni) films exhibit
ferromagnetic behavior up to room temperature. Although the FeAl2O4/STO
is insulating, the NiAl2O4/STO and CoAl2O4/STO
heterointerfaces are found to be highly metallic and exhibit anomalous Hall
effect (AHE) at temperatures below 30 K. Their Hall mobility is as high as 3 ×
104 cm2V-1s-1, comparable to that
of γ-Al2O3/STO interface. There has been evidence of
oxygen-vacancy-related magnetism in γ-Al2O3/STO at
temperatures below 5 K, while the enhanced AHE in NiAl2O4/STO
and CoAl2O4/STO likely comes from the magnetic proximity
effect induced by the top ferromagnetic MAl2O4
spinel films.
Original language | English |
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Article number | 261603 |
Journal | Applied Physics Letters |
Volume | 113 |
Issue number | 26 |
Number of pages | 5 |
ISSN | 0003-6951 |
DOIs | |
Publication status | Published - 2018 |