Inorganic structures in space group P3m1; coordinate analysis and systematic prediction of new ferroelectrics

Area of Science:

• Crystallography and Materials Science
• Solid-State Physics and Chemistry

Background:

• The Inorganic Crystal Structure Database (ICSD) Release 2007/1 contains 311 entries under the polar space group P3m1.
• Ferroelectric materials exhibit spontaneous electric polarization, crucial for various electronic applications.

Purpose of the Study:

• To identify potential ferroelectric materials from a specific subset of the ICSD.
• To analyze atomic arrangements for deviations indicating a potential transition to nonpolar symmetry.

Main Methods:

• Computational analysis of atomic coordinates for 311 inorganic crystal structures in the polar space group P3m1.
• Selection criteria based on the detection of an approach to nonpolar supergroup symmetry within specified limits.
• Exclusion of structures with high uncertainty or low ferroelectric potential, such as many CdI2, ZnS, and SiC polytypes.

Main Results:

• Twelve families of inorganic crystal structures were identified as candidate ferroelectrics.
• Specific candidate materials include In(2)ZnS(4), TlSn(2)F(5), and Bi(HCOO)(3), among others.
• Twenty structures were predicted to be nonpolar, 20 showed reduced predictive properties, and three were likely to retain P3m1 symmetry across a temperature range.

Conclusions:

• The study successfully identified 12 candidate ferroelectric materials from the analyzed crystal structures.
• The reliability of the underlying structural determination is a critical factor influencing the confidence in these predictions.
• Further experimental validation is necessary to confirm the ferroelectric properties of the identified candidates.