Mechanically deformable organic ferroelectric crystal with plasticity optimized by fluorination

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Conventional ferroelectric crystals are typically brittle, limiting their application in flexible devices.
• Achieving plastic deformation in ferroelectric materials is crucial for developing robust and adaptable electronic components.

Purpose of the Study:

• To design and synthesize a novel flexible organic ferroelectric crystal with significant plastic deformability.
• To investigate the impact of anion fluorination on the ferroelectric and mechanical properties of organic crystals.

Main Methods:

• Anion fluorination was implemented on phenylethylammonium mesylate (PEA-MS) to create phenylethylammonium trifluoromethanesulfonate (PEA-TFMS).
• The crystal structure, ferroelectric properties, and mechanical deformability (plasticity, bending, spiral deformation) of PEA-TFMS were characterized.

Main Results:

• The first observation of significant plastic deformation in bulk organic ferroelectric crystals since 1956 was achieved.
• PEA-TFMS exhibits switchable spontaneous polarization and remarkable macroscopic bending and spiral deformability.
• Fluorination subtly modified ionic interactions, leading to a re-organized dipole arrangement and enhanced mechanical flexibility.

Conclusions:

• Fluorination of anions is an effective strategy for designing mechanically deformable organic ferroelectric crystals.
• PEA-TFMS represents a promising candidate for flexible and wearable electronic applications.
• This work provides inspiration for the development of next-generation flexible electronics based on plastic ferroelectric materials.