High-Temperature Synthesis and Dielectric Properties of LaTaON2

Augustin Castets, Ignasi Fina, Jhonatan R. Guarín, Judith Oró-Solé, Carlos Frontera, Clemens Ritter, Josep Fontcuberta*, and Amparo Fuertes*

Inorg. Chem. 2021, 60, 16484−16491;  DOI: doi.org/10.1021/acs.inorgchem.1c02325

 

The development of new synthetic methodologies of perovskite oxynitrides is challenging but necessary for the search of new compounds and the investigation of their properties. Here, we report on the synthesis of LaTaO1+xN2-x under N2 at 1500 °C, that allows to obtain highly sintered compounds with x ≤ 0.35, suitable for dielectric characterization. It is found that of LaTaO1+xN2-x crystallizes in the monoclinic space group I2/m. In contrast to earlier reports, two anion sites show strongly preferred occupancy by nitride indicating a dependence of the anion distribution on the synthetic approach. The dielectric permittivity for LaTaON2 (εr ≈ 200), reported for the first time, is similar to that observed in perovskites with one nitrogen per formula