Fig. 3: Optical second harmonic generation (SHG) measurements of SrTiO3 membranes.
From: Strain-induced room-temperature ferroelectricity in SrTiO3 membranes
a Schematic illustrating the experimental setup for SHG measurements, wherein a 900 nm fundamental beam is used to excite the frequency-doubled signal from membranes in a reflection geometry that can be probed at a wavelength of 450 nm. b SHG polar plots measured at room temperature as a function of incident beam polarization in membranes strained at 2.0%. c SHG signals measured as a function of temperature in membranes strained at 0.9%. d Tc plotted as a function of uniaxial strain directly measured from the SHG measurements, as well as high temperature extrapolations of the Ginsburg–Landau–Devonshire model. Error bars represent the standard deviation.
