Electronic devices often rely on components made of ceramic materials with a polycrystalline microstructure made up of many single crystal grains. The boundaries between these grains interact with nearby point defects (missing or misplaced atoms/atom clusters), changing the material’s properties.
Prof. Douglas Irving’s group has recently developed a multiphysics tool to study the effects of grain boundaries on the point defect chemistry and resulting electrical conductivity of polycrystalline strontium titanate. As demonstrated, the grain boundary consists of a space charge layer that dramatically perturbs the local defect chemistry and thus the resultant local conductivity. When the grain size shrinks from microscale to nanoscale, adjacent space charge layers begin to overlap and eventually cover the entire grain interior, leading to significant changes to the electrical conductivity.
The article written by Yifeng Wu, Preston Bowes, Jonathon Baker, and Douglas Irving was selected as an Editor’s Pick and was featured as a SciLight by the Journal of Applied Physics [Link] and a NCSU News Release [Link]. The research of this paper was supported by the Materials with Extreme Properties led by Dr. Ali Sayir of the Air Force Office of Scientific Research. The full article can be found in the Journal of Applied Physics [Link]. The article can be cited as Y. Wu, P. C. Bowes, J. N. Baker, and D. L. Irving, J. Appl. Phys. 128 1, 014101.