Bulk synthesis of Ce-Ta-N ternary nitride materials

Despite intriguing potential for application in electronics, magnetism, and ferroelectrics, ternary nitrides are a fairly unexplored material class compared to ternary oxides, halides, and chalcogenides. Advances in this interesting family are stagnated by synthetic challenges, such as the often preferential formation of volatile N₂ , which has one of the strongest bonding energies, as well as highest rate of metastability among inorganic compositions, which prevents fine control of reaction outcomes. This talk will investigate the Ce–Ta–N chemical space, in which a novel perovskite phase was just reported as a ferroelectric thin film. Nitride perovskites ABN₃ are difficult to synthesize in bulk, generally requiring both high pressure and high temperature. Using in-situ powder X-ray diffraction, we monitored various metathesis reactions and discovered the formation of perovskite CeTaN₃ in bulk for the first time. Metathesis is a much simpler, lower-temperature synthetic technique that does not require high pressure; thus, this is a significant advance in the field of ternary nitrides. The first half of the talk will focus on ex-situ and in-situ synthesis of this material and its elemental and structural characterization, while in the second half the physical properties of Ce-Ta-N phases will be discussed.