Exploring Metastable Oxynitrides by Thin Film Growth Approach

Metal oxynitrides are expected to show unique chemical and physical properties suitable for various applications. However, compared with oxides, the chemical space of oxynitrides has not been well explored mainly due to their thermal instability and high reaction temperature required in conventional bulk synthesis methods. Highly nonequilibrium thin film growth is a promising route for obtaining those unexplored oxynitrides. In this account, we will overview recent studies on thin film synthesis of oxynitrides, especially focusing on exploration of metastable phases, such as mid- and late-transition metal compounds, metastable polymorphs, geometrical isomers with respect to anion coordination, and amorphous phases.