Friction imprint effect in mechanically cleaved BaTiO3 (001)

Abstract

Adsorption, chemisorption, and reconstruction at the surfaces of ferroelectric materials can all contribute toward the pinning of ferroelectric polarization, which is called the electrical imprint effect. Here, we show that the opposite is also true: freshly cleaved, atomically-flat surfaces of (001) oriented BaTiO 3 exhibit a persistent change in surface chemistry that is driven by ferroelectric polarization. This surface modification is explored using lateral force microscopy (LFM), while the ferroelectric polarization is probed using piezoresponse force microscopy (PFM). We find that immediately after cleaving BaTiO 3 , LFM reveals friction contrast between ferroelectric domains. We also find that this surface modification remains after the ferroelectric domain distribution is modified, resulting in an imprint of the original ferroelectric domain distribution on the sample surface. This friction imprint effect has implications for surface patterning as well as ferroelectric device operation and failure. a) This research was performed while D. Ebeling and S. D. Solares were at the

Switchable tribology of ferroelectrics

“…Friction and wear are complex tribological phenomena in which contributions of several possible micro/nanoscopic mechanisms could lead to the observed asymmetry of these responses in ferroelectrics 24 . Previous studies have already reported on the asymmetric lateral force microscopy signals of ferroelectric single crystals 25 , 26 , but at a few tens of nN loading force, such asymmetry might come from the effects of screening charges or adsorbates on the surface. However, if the friction properties are indeed governed by screening conditions or adsorbates (especially chemisorbed species), the asymmetry should disappear with continuous milling scans, as any surface species or asymmetric skin layers are gradually removed.…”

Inhomogeneous Friction Behaviour of Nanoscale Phase Separated Layered CuInP2S6

“…It is found that the friction of upward domains is higher than downward domains in freshly cleaved BaTiO 3 surfaces. [ 34 ] Also, it is reported that friction is lower in the upward domains of BiFeO 3 ferroelectric thin films. [ 35 ] Recently, based on first‐principles calculations, it is predicted that the friction behavior is different for three different polarization states in 2D ferroelectric In 2 Se 3 : O–O(AP) (tail‐to‐tail out‐of‐plane polarization with antiparallel in‐plane polarization), I–O(P) (downward out‐of‐plane polarization with parallel in‐plane polarization), and I–I(AP) (head‐to‐head out‐of‐plane polarization with antiparallel in‐plane polarization).…”

First‐principles study of the atomic structures, electronic properties, and surface stability of BaTiO3 (001) and (011) surfaces

“…Total energy surfaces of BaTiO 3 , phase transitions in BaTiO 3 ultrathin films, and domain ordering of strained BaTiO 3 (001) films have been investigated by using the first‐principles calculations. The relative experimental works of BaTiO 3 surfaces have been further developed …”