Fig. 1: Straining SrTiO3 membrane.
a Two scenarios of the strain-induced ferroelectric transition: displacive (left) and order-to-disorder (right). b Schematic of the uniaxial strain applied onto SrTiO3 sample supported by polyimide films. The device is suspended over a hundred-µm gap defined by two cleaved silicon substrates. The schematic drawing is not to scale. c Image of the SrTiO3 sample near the gap area. d–f Single crystal X-ray diffraction of three Bragg peaks [(002), (202), (022), in pseudocubic notation] during the tensile strain and release process at 40 K. g Refined lattice parameters of the strained SrTiO3 with different applied forces along crystallographic a direction via piezo stacks. h The relationship between the lattice strain of two relevant lattice parameters, namely the length along the strain \({\varepsilon }_{a}=\Delta a/{a}_{0}\) and out-of-plane \({\varepsilon }_{c}=\Delta c/{c}_{0}\), for selected temperatures, where \({a}_{0}\) and \({c}_{0}\) are the lattice constants at zero strain.
