The First Ferrocene-Based Molecular Ferroelectric Accompanied by Spatial Symmetry Operation Breaking

Area of Science:

• Materials Science
• Solid-State Chemistry
• Crystallography

Background:

• Ferroelectric materials possess switchable spontaneous polarization, crucial for electronic devices.
• Molecular ferroelectrics offer advantages like tunability and ease of processing over ceramics.
• Developing single-component ferrocene-based ferroelectrics presents a significant challenge.

Purpose of the Study:

• To report the first chiral, single-component ferrocene-based ferroelectric.
• To investigate its structural phase transition and ferroelectric properties.
• To explore new avenues for designing advanced ferroelectric materials.

Main Methods:

• Synthesis of a novel chiral ferrocene derivative using a homochirality strategy.
• Characterization using piezoresponse force microscopy and polarization-electric field hysteresis loops.
• Validation of non-centrosymmetric structure via polarized second-harmonic generation measurements.

Main Results:

• Successfully synthesized and identified a single-component, chiral ferrocene-based ferroelectric.
• Observed a reversible structural phase transition at 193 K from polar space group C2 to P2₁.
• Confirmed ferroelectric nature and non-centrosymmetric structure.

Conclusions:

• This work presents the first homochiral, single-component ferrocene-based ferroelectric.
• The material undergoes phase transitions involving only spatial symmetry operation breaking.
• Offers valuable insights for designing new chiral and ferrocene-based ferroelectrics.