Researchers at KAIST, in collaboration with multiple institutions, have experimentally confirmed the three-dimensional vortex-shaped polarization distribution inside ferroelectric nanoparticles. Using atomic electron tomography, they mapped atomic positions in barium titanate nanoparticles and calculated the internal polarization distribution. This finding confirms theoretical predictions made 20 years ago and holds potential for developing ultra-high-density memory devices.
It is well-known that ferromagnets lose their magnetic properties when reduced to nano sizes below a certain threshold. What happens when ferroelectrics are similarly made extremely small in all directions has been a topic of controversy for a long time.
Using atomic electron tomography, the team completely measured the positions of cation atoms inside barium titanate nanoparticles, a well-known ferroelectric material, in three dimensions. From the precisely determined 3D atomic arrangements, they were able to further calculate the internal three-dimensional polarization distribution at the single-atom level.
By controlling the number and orientation of these polarization distributions, it is expected that this can be utilized into next-generation high-density memory devices that can store more than 10,000 times the amount of information in the same-sized device compared to existing ones.