A recent work by the Fernandez-Serra group published in Nature Physics entitled Flexoelectricity and surface ferroelectricity of water ice was featured in the Stony Brook University News:

Stony Brook University PhD student Anthony Mannino, working under the supervision of Professor Marivi Fernandez-Serra in the Department of Physics and Astronomy and the core faculty at the Institute for Advanced Computational Science (IACS), spearheaded the theoretical side of the project. It was discovered that ice exhibits strong flexoelectricity — an electromechanical effect that occurs when the material is bent.

The international collaboration was led experimentally by Professor Gustau Catalan and Xin Wen at the Institut Català de Nanociència i Nanotecnologia (ICN2) in Barcelona.

Using the Seawulf supercomputing cluster, Mannino performed large-scale quantum simulations that revealed how the surface of ice can undergo subtle ferroelectric ordering at low temperatures. This ordering amplifies the flexoelectric effect and explains how collisions between ice particles and graupel in thunderclouds can generate the massive charge separations that lead to lightning.

Members of the Fernandez-Serra Group, led by Dr. Alec Wills, were recently featured in a Science Story on the Ookami webpage regarding their recent publication in Physical Review Research:  Anti-Coulomb ion-ion interactions: a theoretical and computational study.

“Picture a dance floor where the usual rules of attraction and repulsion go haywire. In a solvent (like water) like-charged ions (normally wallflowers) decide to dance together, while oppositely charged ions (the usual dance partners) awkwardly avoid each other. This surprising behavior is due to the solvent’s quirky non-local dielectric response function. While this had previously only been linked to a well known phenomenon called ‘overscreening’, researchers from Stony Brook University and the Universidad Autónoma de Madrid have shown that this behavior is always expected whenever a solvent has a sufficiently strong dielectric response.”

Figure: The bound-state depth for dressed-dressed interactions in the TF approximation as a function of its location, colored by the screening parameter . The bound state depth gets weaker with increasing screening length, and the position of the minimum shifts to farther separations. The numerical results agree well with the analytical expressions.

Highlight

Drs. Marivi Fernández-Serra, Cyrus Dreyer, Matt Dawber, and collaborators have revealed the mechanism behind the splitting of water at the surface of strontium titanate (SrTiO3).

Water at the surface of the SrTiO3 can use the energy of an incoming photon to split into hydrogen (H2), an eco-friendly fuel source, and oxygen.

Similar methods of splitting water have faced difficulties achieving the needed efficiency to be practical, and the exact mechanism of the splitting was not well understood. This new research could pave the way for more systematic searches of efficient photocatalyst surfaces.

The published article has been highlighted by PRX here.