Comment on "Interesting Evidence for Template-Induced Ferroelectric Behavior in Ultra-Thin Titanium Dioxide Films Grown on (110) Neodymium Gallium Oxide Substrates"

Abstract

X-ray diffraction, second-harmonic generation and infrared reflectance investigations reveal no evidence for a polar phase or ferroelectric phase transition in 1.6% tensile strained anatase TiO2 thin films. This indicates that the previously-reported potential ferroelectric behaviour, observed using piezoelectric force microscopy, may have been defect related, or the polar distortion is too small to detect using these methods.