Surveying polar materials in the Inorganic Crystal Structure Database to identify emerging structure types

Abstract

Here we focus on a search for new families of materials that could contain ferroelectrics via crystallographic database mining. Ferroelectrics are insulating polar materials whose polarization can be switched with the application of an electric field. They already find use in a variety of technologies, but new types of ferroelectrics could operate in extended regimes of temperature and pressure, maintain polarization in thin film form, and have the potential to couple to additional functional properties like magnetism and thermoelectricity. One route to find new example ferroelectrics is to search for materials whose polarization is a consequence of their crystal structure. Here we search for families of polar materials within the Inorganic Crystal Structure Database (ICSD), revisiting a prior survey of polar space groups to better understand how trends in the number and type of polar materials in the ICSD change over time. We classify the polar materials by crystal class, space group, the number of distinct elements, and finally structure types. We compare the data collected in August 2019 to the original survey data to identify a diverse set of emerging polar structure types in the ICSD that warrant further exploration as families that may contain new example ferroelectrics.