Young's modulus of freestanding oxide thin films

Recent developments in thin film growth provide a powerful route to free-standing single-crystal films of perovskite oxides by water etching of a sacrificial underlayer (Di Lu et al., Nature Materials 15, 1255 [2016]). We have used Atomic Force Microscopy to systematically probe the elastic properties of suspended SrTiO₃ films, in the hitherto unexplored sub-100 nm thickness regime. We evaluate and discuss the variation of Young's modulus with film thickness, and compare our freestanding films to bulk SrTiO₃. Our study of the mechanical properties of thin SrTiO₃ could provide the basis for precise strain control and manipulation of complex oxides at the nanoscale, thus coupling to spin-charge-orbital degrees of freedom, as well as ferroic order.