Some materials called "ferroelectrics" can align robustly their electrical dipoles in two directions providing two distinct information states, among which one can switch by applying an electric field. This sets ferroelectrics among the best candidates for future non-volatile RAM memories (FeRAMs). But for that to become a reality, some issues related to device miniaturization need to be addressed: the dipoles are typically perpendicular to the ferroelectric surface but they loose their stability when the material is scaled down to the nanometer size. An alternative to avoid this drawback would be using a material with in-plane dipoles, but that has never been considered a viable option because these dipoles are known to be very hard to switch, due to the intense strain difference between the two states. In this paper, Matzen et al. report a novel mechanism that allows switching of in-plane ferroelectric dipoles by creating differently oriented regions of parallel dipoles (domains) at two different length scales (nanodomains and superdomains) such that the average stress field is neutralized. This allows switching in-plane electrical dipoles with the voltage applied to the tip of an atomic force microscope (see figure). The authors have coined this novel mechanism as "Super switching". The work is collaboration between the Zernike Institute (group of Beatriz Noheda) and the Oak Ridge National Lab (US).
RUG verleent eredoctoraat aan voormalig VN secretaris-generaal Ban Ki-moon
RUG op plek 39 in Europe Teaching Excellence ranking
De Wierenga-Rengerinkprijs voor de RUG-promovendus met de beste dissertatie in 2017, is toegekend aan dr. Alain Dekker voor zijn proefschrift ‘Down & Alzheimer: Behavioural biomarkers of a forced marriage’.