Nanostructural and piezoelectric characterization of electro-formed δ-phase poly(vinylidene fluoride) thin films

ABSTRACT

Ferroelectric polymer PVDF possesses different polymorphs. Solution-processed thin films crystallize mostly into the paraelectric α-phase. From α-PVDF, the electroactive phases β-, γ-, δ-PVDF can be achieved by further treatments. For instance, δ-PVDF, also known as α_p-phase, can be obtained by electro-forming. In this work, we study the α-PVDF surface morphology using atomic force microscopy through a high-resolution image at the sub-nanometre scale. We go through the ferro- and piezoelectric properties of the electro-formed δ-PVDF thin films and we present an electro-mechanical characterization in high-fields regime, for studying the non-linear electrostrain behaviour, and in low-fields regime, for extracting the piezoelectric coefficient.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

The capability of atomic force microscopy to investigate surfaces at sub-nanometre scale is applied for a direct observation of polymer chains within the crystalline lamellae at the unit-cell length characteristic.

KEYWORDS:

• PVDF
• AFM
• nanoscale
• δ-phase
• piezoelectricity

Acknowledgement

The authors acknowledge TU Wien Bibliothek for financial support through its Open Access Funding Program.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This project is funded by the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology, BMK, and is carried out as part of the Production of the Future program.