Superconductivity in Ti2O3 films on MgO substrate

Transition metal oxide films exhibit strong structure-property correlations, which foster innovative physical properties that are not present in their bulk counterparts. This study has successfully prepared different thickness-dependent epitaxial Ti2O3 thin films on MgO (001) single crystal substrate using the pulsed laser deposition method. The results reveal a strong correlation between the crystal structure and superconductivity in Ti2O3 thin films. Synchrotron x-ray diffraction and high resolution transmission electron microscope measurements confirmed that the appearance of superconductivity is closely related to the coexistence of the cubic-Ti2O3 (gamma-Ti2O3) and orthorhombic-Ti2O3 (o-Ti2O3) phases. Superconductivity is absent in 80 nm film, which exhibits only a single gamma-Ti2O3 phase. The highest superconducting transition temperature (T (C)) similar to 7.2 K is achieved in 1200 nm film, which shows about 55% o-Ti2O3 phase and 45% gamma-Ti2O3 phase. Room temperature Raman data suggest that E (g) modes at similar to 330 and similar to 430 cm(-1) may associate with superconductivity, and an E (g) mode at similar to 660 cm(-1) is related to the insulating behavior observed in 80 nm film.

Automated summary

Transition metal oxide films exhibit strong structure-property correlations, and this study successfully prepared thickness-dependent epitaxial Ti2O3 thin films, revealing a correlation between crystal structure and superconductivity.