来源：ACS Publications Designing functional materials is a promising route to enhance modern technologies. Here, an unreported hexagonal perovskite, LuGaO3, is successfully synthesized in thin-film form, and its structure is characterized and compared to isostructural LuFeO3, along with solid solutions of the two (LuFexGa1–xO3, for x = 0.25–0.75). The addition of gallium was found to degrade the structural quality of LuFeO3, rendering the hexagonal phase nearly unobservable in pure LuGaO3. Extensive growth experiments (and thermodynamic phase diagrams for related systems) suggest a tendency for LuGaO3 to decompose into Lu2O3 and Lu3Ga5O12. In turn, unconventionally high synthesis pressures (500–2000 mTorr) during pulsed-laser deposition are required to stabilize the hexagonal phase. While device-based measurements demonstrate an obvious ferroelectric hysteresis for LuFeO3, the addition of gallium (seemingly) quenches any observable ferroelectric polarization while also lowering the leakage and dielectric constant. Second-harmonic-generation measurements and piezoresponse force microscopy, however, indicate that LuGaO3 is polar and can be switched under an electric field. This discrepancy with device-based measurements warrants further study, upon improving the structural quality, before ferroelectricity can be claimed unequivocally. These findings demonstrate that designer materials can be synthesized, but further refinement to predictive approaches is needed to bring them more in-line with experimental reality. This work demonstrates that it is indeed possible to synthesize hexagonal LuGaO3 in thin-film form but that its stability is not as straightforward as predictions would suggest. Alloys of the form LuFexGa1–xO3 (x = 0.25, 0.5, and 0.75) were synthesized via pulsed-laser deposition (PLD) and compared to LuGaO3 and LuFeO3 end members. While LuFeO3 exhibits the expected hexagonal structure, the film quality degrades significantly with the addition of gallium. Further investigation into pure LuGaO3 films, grown under similar parameters as LuFeO3, revealed a strong preference for phase separation into Lu2O3 and Lu3Ga5O12 phases, where high-quality epitaxial films of each could be grown on Y0.08Zr0.92O2 (YSZ) and Y3Ga5O12 substrates, respectively.