Robust ferroelectricity in low-dimensionalδ-SiX (X = S/Se): a first-principles study

Abstract

Low-dimensional ferroelectric materials hold great promise in nonvolatile memories. In this work, the ferroelectricity in two-dimensional monolayers and one-dimensional nanowires based on δ-SiX (X = S, Se) materials, including spontaneous...

First-principles prediction of ferroelectric Janus Si2XY (X/Y = S/Se/Te, X ≠ Y) monolayers with negative Poisson's ratios

“…41,42 By employing the MD simulations for 10 ps, the average ionic displacement is calculated using the formula to describe the magnitude of polarization, where x X − x Y represents the coordinate differences along the a -axis between the adjacent X and Y atoms and N represents the sum of X–Y atom pairs in the supercell. 43 As shown in Fig. 5(d), d x between S and Se atoms is 0.73 Å at 0 K, in accordance with the P s of 1.632 × 10 −10 C m −1 .…”