Pressure-induced ferroelectric phase of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LaMoN</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>
Churen Gui, Shuai Dong
Abstract
Nitride perovskites are supposed to exhibit excellent properties as oxide analogs and may even have a better performance in specific fields for their more covalent characters. However, until now, very limited nitride perovskites have been reported. In this Rapid Communication, a nitride perovskite ${\mathrm{LaMoN}}_{3}$ has been systematically studied by first-principles calculations. The most interesting physical property is its ferroelectric $R3c$ phase, which can be stabilized under a moderate hydrostatic pressure ($\ensuremath{\sim}1.5$ GPa) and probably remain metastable under an ambient condition. Its ferroelectric polarization is considerably large, $80.3\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{C}/{\mathrm{cm}}^{2}$, driven by the nominal $4{d}^{0}$ rule of ${\mathrm{Mo}}^{6+}$, and the covalent hybridization between Mo's $4d$ and N's $2p$ orbitals is very strong. Our calculation not only predicts a ferroelectric material with prominent properties, but also encourages more studies on the pressure engineering of functional nitrides.