Full text loading...
Arrhenius plot of oxygen partial pressure vs. reciprocal temperature showing where LuFe2O4 is thermodynamically stable.
(a) Substrate model for MgO, MgAl2O4, and 6H-SiC with the (111), (111), and (0001) planes of the substrate surface highlighted, respectively. (b) The epitaxial orientation relationship of a LuFe2O4 lattice on (111) MgO, (111) MgAl2O4, and (0001) 6H-SiC lattices (see Ref. 21). (c) A model showing the alternating single layers of lutetium oxide (U layers, Ref. 24) and double layers of iron oxide (W layers, Ref. 24) in LuFe2O4. (d) θ-2θ x-ray diffraction scans for three 50 nm thick LuFe2O4 films grown on (111) MgAl2O4, (111) MgO, and (0001) 6 H-SiC. Asterisks (*) indicate XRD peaks from the substrates.
HAADF-STEM images of the same LuFe2O4 on MgAlO4 film studied in Fig. 2(d) showing (a) the presence of a clean interface and (b) the well-ordered structure of LuO1.5 U layers alternating with Fe2O2.5 W layers. An overlay of a single unit cell is shown in the lower corner of (b).
The magnetization as a function of temperature and magnetic field of the same LuFe2O4 films as in Fig. 2(d).
Optical response of a 75 nm thick (0001) LuFe2O4 film grown on (111) MgAl2O4 along with the ab-plane response of a LuFe2O4 single crystal (Ref. 28) at 300 K. The film absorption was determined by a combination of direct calculation of absorption from transmittance (below ∼3 eV) and a Glover-Tinkham analysis of both transmittance and reflectance to obtain absorption above 3 eV. The data were merged between 2.5 and 3 eV, where there was substantial overlap. The inset shows the indirect and direct band gap analysis.
LuFe2O4 film lattice parameters and rocking curve full width at half maximum (FWHM) values determined from XRD data.
Article metrics loading...