Structural, Electronic, and Ferroelectric Properties of Compressed CdPbO3 Polymorphs

On the basis of density functional theory (DFT) and hybrid functional, we report a first-principles study for the structural, electronic, and ferroelectric properties of the two recently synthesized high-pressure polymorphs of CdPbO3 with perovskite-type (Pnma) and LiNbO3-type (R3c) structures. Besides providing the structural transformation and electronic results, we predict the realization of proper ferroelectric behavior in LiNbO3-type CdPbO3. On the basis of the Berry phase theory, the spontaneous electronic polarization is calculated as 52.3 μC/cm2 along the [111] direction. The origin of the ferroelectric behavior is discussed and explained in terms of the analysis of Born effective charges, potential-energy surfaces, charge density isosurfaces, and electric localization function.