Epitaxially stabilized growth of orthorhombic LuScO_3 thin films

摘要

Metastable lutetium scandate (LuScO_3) thin films with an orthorhombic perovskite structure have been prepared by molecular-beam epitaxy and pulsed-laser deposition on NdGaO_3(110) and DyScO_3(110) substrates. Stoichiometry and crystallinity were investigated using Rutherford backscattering spectrometry/channeling, x-ray diffraction, and transmission electron microscopy. The results indicate that LuScO_3, which normally only exists as a solid solution of Sc_2O_3 and Lu_2O_3 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 200 nm for the epitaxially stabilized perovskite polymorph of LuScO_3 on NdGaO_3(110) substrates was determined.