Nanoscale modulations in Li- free perovskites: platform for new checkerboard chemistries

1. Nanoscale Modulated Structures in Li-based PerovskitesPeter K. Davies, University of Pennsylvania, DMR 0704255 A major objective in nanoscale science is realizing structures where the organization of the constituent nano-building blocks is perfect, periodic and functionally modulating. In this project we discovered a unique family of ceramic materials with periodic phase-separated nanostructures where the phases comprise compositional and functional contrast. These “nanocheckerboard” systems, prepared using standard ceramic processing methods, were first discovered in the (Nd,Li)TiO3 system. By incorporating transition metal substituents (e.g. Mn3+) capable of magnetic and electronic interactions, new types of nano-morphologies have been identified, these may enable unique collective functional responses. This year we also discovered these unique structures can be stabilized in Li-free systems, opening avenues to a completely new range of chemistries and properties. • Nanocheckerboards in NdMnO3-(Nd1/2Li1/2)TiO3 • Mn-rich borders • Li/Ti rich islands 10 nm • Nanoscale modulations in Li- free perovskites: • platform for new checkerboard chemistries