Regensburg 2022 – scientific programme

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 31: Electrical, Dielectrical and Optical Properties of Thin Films (joint session CPP/KFM)

KFM 31.1: Talk

Friday, September 9, 2022, 11:30–11:45, H38

Mechanical nanoscale polarization switching in ferroelectric polymer films — •Kathrin Dörr, Martin Koch, Diana Rata, and Robert Roth — MLU Halle-Wittenberg

Ferroelectric polymer films offer strong advantages like mechanical flexibility, biocompatibility, optical transparency and low-cost processing. However, their dielectric or piezoelectric performance is often inferior to that of oxide ferroelectric materials. Key to that is the electric dipolar order which is naturally lower in semicrystalline polymers than in crystalline ferroelectrics. We introduce the reorientation and alignment of the electric polarization in thin films utilizing the mechanical effect of an unbiased scanning force microscopy tip, providing a versatile tool for nanoscale domain writing [1]. Thin films (50 - 150 nm) of P(VDF-TrFE) (78:22) on graphite were prepared with dense (110)-oriented beta-phase lamellae randomly oriented in the film plane. Domain patterns with resolution down to 50 nm have been written with four (out of six possible) local polarization orientations. Written domains show excellent long-time stability. We discuss a ferroelastic origin of the mechanical polarization switching and make suggestions for how to utilize the domain patterns in thin film devices. [1] Adv. Electron. Mater. 2022, 2101416