Ferroelectric-like Polarization Switching in Plastic Crystalline Succinonitrile

Area of Science:

• Materials Science
• Solid-State Physics
• Organic Electronics

Background:

• Plastic crystal (PC) phase offers potential for advanced materials.
• Maintaining molecular order in PC phase is challenging due to isotropic rotation.
• PC phase applications include ionic conductors, ferroelectrics, and barocaloric materials.

Purpose of the Study:

• To realize and investigate a unique polarized orientation state in the PC phase of sucinonitrile (SN).
• To understand the polarization mechanisms and P-E hysteresis behavior in SN's PC phase.
• To explore the potential of SN for next-generation multilevel memory applications.

Main Methods:

• Investigated sucinonitrile (SN) in its plastic crystal (PC) phase.
• Applied external electric fields to observe polarization-electric field (P-E) hysteresis.
• Analyzed molecular conformation (trans and gauche) and orientation changes under electric fields.

Main Results:

• Achieved a unique polarized orientation state in SN's PC phase, exhibiting P-E hysteresis.
• Observed relaxation of polarization upon electric field removal, unlike conventional ferroelectrics.
• Discovered two distinct polarization mechanisms arising from molecular orientational and conformational freedom.
• Characterized a unique double P-E hysteresis with two coercive fields, not seen in conventional ferroelectrics.

Conclusions:

• Succonitrile's PC phase exhibits unique polarization behavior driven by molecular conformation and orientation.
• The observed double hysteresis offers a new pathway for designing materials for multilevel memory.
• Findings provide crucial insights for developing novel organic materials for advanced electronic applications.