Aluminum nitride crystals containing scandium physically inflate under the pressure of their own internal electric fields.
Scandium aluminum nitride crystals consistently showed electrical properties that defied every theoretical prediction for years. This material actually inflates like a pressurized vessel because its internal electric fields are strong enough to push the atoms apart. Engineers previously assumed the crystal structure remained rigid, but this microscopic swelling accounts for the missing data in their measurements. These specific alloys are the backbone of modern 5G signal filters and high-speed acoustic sensors. Manufacturers can now predict exactly how these chips will perform before they are built. Future smartphones will benefit from more precise hardware that wastes less power and handles more data.
The high K anomaly in ScAlN explained
arXiv · 2605.03765
We resolve the long-standing discrepancy between theoretical material constants and experimental observations of the dielectric response in scandium aluminum nitride (ScAlN). While first-principles calculations of the rigid lattice predict a permittivity of about 11.7, experiments consistently report values near 15. We demonstrate that this "high K" behavior is a manifestation of electromechanical inflation, where the enormous internal electric fields of polar heterostructures induce macroscopic