Barium titanate is one of the essential ferroelectrics. It has a tetragonal crystalline structure and can be produced in the form of fibers.
Barium titanate applications are wide-ranging. Despite having various applications, scientists are unclear about its working. Some theoretical models out there, but some of their key predictions have never been experimentally confirmed.
Recently, EPFL scientists have made an important discovery about the structure of barium titanate. They used Titan Themis – one of the world’s most powerful electron microscopes – for their research that enabled them to observe the atomic structures of barium titanate and barium-strontium titanate in the cubic phase.
Emad Oveisi, a senior scientist at EPFL’s Interdisciplinary Center for Electron Microscopy, said, “Until now, researchers believed that the atoms move in several directions in a concise timeframe. But our experiments showed that they tend to prefer certain directions, meaning there are nanometric-sized areas where all the atoms move in the same way. That completely changes how we view these materials and their atomic structure.”
Along with collaborators in Slovenia, Austria, and Japan, scientists took five years to finalize the results.
Scientists later identified the region where the atoms in the material move in an orderly fashion. Here, movements refer to the displacements on a picometer scale – that is, one order of magnitude smaller than the atoms themselves.
Damjanovic said, “Even though the displacements are extremely small, they have repercussions on a much larger scale. For instance, if we expose the nanometric areas we identified to a high-frequency electric field like those in smartphones, the areas heat up.”
The findings have important implications in better understanding energy loss in these kinds of materials.
- Andreja Ben can et al. Atomic-scale symmetry and polar nanoclusters in the paraelectric phase of ferroelectric materials. DOI: 10.1038/s41467-021-23600-3