Local piezo- and ferroelectric properties of γ-glycine single crystal observed via piezoresponse force microscopy

Abstract

In this work, we demonstrate an approach of local mechanical polishing processing to modify the type of intrinsic piezoelectric activity of γ-glycine polymorph grown in a form of a single crystal. By using the piezoresponse force microscopy, the increase in intensity for both out-of-plane (3 times) and in-plane (5 times) piezoelectric tensor components is demonstrated. Application of local switching spectroscopy reveals the piezoelectric behavior of non-polished and the ferroelectric behavior of polished areas being related to the local mechanical polishing-assistant rearrangement of NH 3+ tails of zwitterions in polymorph molecular chain of γ-glycine. These rearrangements were demonstrated to facilitate the switching behavior of the local dipole moment at the applied electric field surpassing the internal coercive field of about Ec ∼ 3 G V /m .