title: Differentiating Ferroelectric and Nonferroelectric Electromechanical Effects with Scanning Probe Microscopy.
abstract: Ferroelectricity in functional materials remains one of the most fascinating areas of modern science in the past several decades. In the last several years, the rapid development of piezoresponse force microscopy (PFM) and spectroscopy revealed the presence of electromechanical hysteresis loops and bias-induced remnant polar states in a broad variety of materials including many inorganic oxides, polymers, and biosystems. In many cases, this behavior was interpreted as the ample evidence for ferroelectric nature of the system. Here, we systematically analyze PFM responses on ferroelectric and nonferroelectric materials and demonstrate that mechanisms unrelated to ferroelectricity can induce ferroelectric-like characteristics through charge injection and electrostatic forces on the tip. We will focus on similarities and differences in various PFM measurement characteristics to provide an experimental guideline to differentiate between ferroelectric material properties and charge injection. In the end, we apply the developed measurement protocols to an unknown ferroelectric material.
authors.forename: Nina
authors.initials: N
authors.lastname: Balke
authors.forename: Petro
authors.initials: P
authors.lastname: Maksymovych
authors.forename: Stephen
authors.initials: S
authors.lastname: Jesse
authors.forename: Andreas
authors.initials: A
authors.lastname: Herklotz
authors.forename: Alexander
authors.initials: A
authors.lastname: Tselev
authors.affiliation: ∥Materials Science and Engineering, University of Wisconsin, Madison, Wisconsin 53706, United States.
authors.forename: Chang-Beom
authors.initials: CB
authors.lastname: Eom
authors.forename: Ivan I
authors.initials: II
authors.lastname: Kravchenko
authors.affiliation: ⊥State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China.|#Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.|¶RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
authors.forename: Pu
authors.initials: P
authors.lastname: Yu
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Kalinin
keywords: electrostatics; ferroelectricity; relaxors; scanning probe microscopy