|About this Abstract
||MS&T23: Materials Science & Technology
||Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
||Elemental Segregation in Iron Strontium Titanate Solid Solutions
||Dylan Jennings, M. Pascal Zahler, Di Wang, Qianli Ma, Wendelin Deibert, Christian Kübel, Stefan Baumann, Joachim Mayer, Wolfgang Rheinheimer
|On-Site Speaker (Planned)
Perovskite oxides, such as strontium titanate, are of interest for a variety of energy related applications due to their many advantageous properties, including their ionic conductivities. Of particular importance to material performance is the presence of space charge layers at the grain boundaries, which arise from the segregation of charged defects in the material. However, most analyses of space charge layers assume dopant concentrations well below the dilute solute limit. In this work, the interactions between dopant segregation and space charge in Fe doped strontium titanate are investigated with S/TEM at a variety of Fe contents, ranging from near the dilute limit (0.8 at% Fe) to well above the dilute limit (5 at% Fe). Chemical characterization with EDS and EELS shows substantial segregation of Fe to the grain boundaries in all compositions studied. In addition, Electrochemical impedance spectroscopy (EIS) is presented to correlate nanoscale dopant segregation to bulk material properties.