ORNL microscopy inspires flexoelectric theory behind 'material on the brink'

Electron microscopy has led to a new theory to explain intriguing properties in a material with potential applications in capacitors and actuators. An Oak Ridge National Laboratory (ORNL) research team examined thin films of bismuth samarium ferrite, known as BSFO, which exhibits unusual physical properties near its transition from one phase to another. BSFO holds potential as a lead-free substitute for lead zirconium titanate (PZT), a similar material currently used in dozens of technologies from sensors to ultrasound machines. Materials such as BSFO and PZT are often called "materials on the brink" in reference to their enigmatic behavior, which is closely tied to the transition between two different phases. Using scanning transmission electron microscopy, the team mapped the position of atoms in BSFO films to find what happens to the local structure at the transition between ferroelectric and antiferroelectric phases. The team's results are published in Nature Communications.