2θ-ω diffraction pattern from ScN thin film sputtered onto MgO(001) substrate. A rocking curve (insert) of 002 ScN reflection reveals a FWHM of 0.675°.
Plan-view FESEM image of the ScN surface showing the formation of square flat-topped mounds with average estimated feature size of 40 nm.
Plan-view bright-field TEM image of the ScN thin film grown on MgO substrate. Insert is a SAED obtained at  zone axes.
High resolution TEM image of ScN/MgO interface (shown by arrow). The lattice mismatch between the ScN film and the MgO substrate is about 7%. The insert SAED confirms the epitaxial growth of ScN on MgO substrate.
(a) In-plane electrical conductivity and (b) in-plane Seebeck coefficient of a ScN film measured under vacuum in the 300-840 K temperature range. Note that the theoretical Seebeck was set equal to the experimental Seebeck in order to determine the location of the Fermi level at each temperature. The extracted Fermi level was used to compute the electrical conductivity.
Extracted Fermi level and optimal Fermi level, relative to the conduction band edge, versus temperature.
Power factor of a ScN film as a function of temperature. The power factor increases with temperature reaching a maximum value of 3.5 × 10−3 W/mK2 at 600 K. The theoretical power factor was calculated using a mean-free-path for backscattering of 23 nm at 300 K. The optimal power factor was obtained by varying the location of the Fermi level to maximize the power factor.
Calculated densities of electronic states as a function of the oxygen content in ScN films. The Fermi energy shifts in the conduction band as the concentration of oxygen is increased in ScN from 0.00 to 6.25 at. %, while the basic electronic band structure is preserved. Insert is the second-order polynomial fit of (EF-EC) vs. oxygen concentration, which is used to estimate the position of the Fermi energy for oxygen content below 1.56 at. %.
SOD technique analysis for 222 supercell with varying oxygen concentrations.
Total energies of the all SIC's for a 6.25% of oxygen on nitrogen site. The lowest energy corresponds to the SIC-3 where O-O distance is the largest.
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