Dehydration-activated structural phase transition in a two-dimensional hybrid double perovskite

Area of Science:

• Materials Science
• Solid-State Chemistry
• Crystallography

Background:

• Organic-inorganic hybrid double perovskites offer promising lead-free alternatives with properties like ferroelectricity.
• These materials are explored for applications in advanced electronic devices.

Purpose of the Study:

• To investigate the solid-to-solid structural phase transition of a 2D hybrid double perovskite, (CHA)4CuBiI8.
• To explore the effect of dehydration on the material's structural and dielectric properties.

Main Methods:

• Differential scanning calorimetry (DSC) for thermal analysis.
• Temperature-dependent dielectric measurements to study phase transitions.
• Variable-temperature single-crystal X-ray diffractometry to determine structural changes.

Main Results:

• The dehydration of (CHA)4CuBiI8·H2O successfully activated a solid-to-solid structural phase transition.
• The phase transition is attributed to inorganic skeleton distortion, movement, and cationic structure deformation.
• The dehydrated material demonstrated good stability with multiple reversible switching cycles.

Conclusions:

• Dehydration is an effective method to activate structural phase transitions in hybrid double perovskites.
• The findings expand the understanding of hybrid double perovskite properties and potential applications.
• This work highlights the potential of (CHA)4CuBiI8 for stable, switchable electronic devices.