Quasi‐1D Antiferroelectricity in Centrosymmetric CsTaS3 Crystal

Abstract

Abstract1D ferroelectric (FE) materials are expected to be promising low‐dimensional materials for nanometer devices, but are rarely reported. The previous experiment discovered that quasi‐1D CsTaS3 crystalizes in centrosymmetric space group, but in which the Ta cations have a strange shift along the c axis from the center of TaS6 octahedron. Here, the crystal structure, electronic structure, ferroelectric, and piezoelectric properties of CsTaS3 by using first‐principles calculations are studied. It is found that the empty d orbitals of Ta cations induce the distortions of TaS6 octahedra, which bring the polarity along a given [TaS3]− chain. The adjacent chains are antiferroelectric (AFE) coupling making CsTaS3 being an AFE material. However, the FE phase of CsTaS3 is supposed to be accessible since its total energy is only 0.3 meV per formula higher than that of the AFE phase. The polarization of FE CsTaS3 is estimated to be 16.8 μC cm−2, which is comparable to those of well‐known FE perovskites. The work predicts a quasi‐1D AFE material, which would be helpful for subsequent experimental work.