Research project Tilt engineering of Prussian blue analogues towards new multiferroic materials

Multiferroicity is defined as the coexistence, and ideally coupling, between at least two ferroic degrees of freedom, such as ferromagnetism, ferroelectricity, and ferroelasticity. This is of interest for fundamental reasons as well as for the many envisioned applications, e.g. in data storage. However, one great limitation is the lack of compounds that show both magnetic order and symmetries compatible with ferroelectricity. Ferroelectricity refers to the presence of a macroscopic electronic polarisation that can be switched by an electric field, but this is only allowed in polar point groups, which are relatively rare. 

A relatively recent mechanism for the design of new ferroelectric materials is known as tilt engineering, and relies on inducing structural distortions in a material that will lead to the adoption of polar symmetry. This project explores tilt engineering as a mechanism towards polarity in the metal-cyanide family known as Prussian blue analogues. These compounds are highly tunable and show interesting magnetic properties (one of the ingredients in multiferroicity), but the first polar phase (the second ingredient) was only recently discovered.