Epitaxially stabilized growth of orthorhombic $LuScO3$ thin films

Metastable lutetium scandate $(LuScO3)$ thin films with an orthorhombic perovskite structure have been prepared by molecular-beam epitaxy and pulsed-laser deposition on $NdGaO3(110)$ and $DyScO3(110)$ substrates. Stoichiometry and crystallinity were investigated using Rutherford backscattering spectrometry/channeling, x-ray diffraction, and transmission electron microscopy. The results indicate that $LuScO3$⁠, which normally only exists as a solid solution of $Sc2O3$ and $Lu2O3$ with the cubic bixbyite structure, can be grown in the orthorhombically distorted perovskite structure. Rocking curves as narrow as 0.05° were achieved. A critical film thickness of approximately $200nm$ for the epitaxially stabilized perovskite polymorph of $LuScO3$ on $NdGaO3(110)$ substrates was determined.