Related papers: Negative piezoelectricity in quasi-two/one-dimensi…
Negative piezoelectrics contract in the direction of applied electric field, which are opposite to normal piezoelectrics and rare in dielectric materials. The raising of low dimensional ferroelectrics, with unconventional mechanisms of…
In this study, we investigate the underlying mechanisms of the negative piezoelectricity in low--dimensional materials by carrying out first--principles calculations. Two--dimensional ferroelectric CuInP$_2$S$_6$ is analyzed in detail as a…
Piezoelectrics with negative longitudinal piezoelectric coefficients will contract in the direction of an applied electric field. Such piezoelectrics are thought to be rare but there is no fundamental physics preventing the realization of…
Piezoelectric and ferroelectric properties in the two dimensional (2D) limit are highly desired for nanoelectronic, electromechanical, and optoelectronic applications. Here we report the first experimental evidence of out-of-plane…
Multiferroic materials are potential to be applied in novel magnetoelectric devices, for example, high-density non-volatile storage. Last decades, research on multiferroic materials was focused on three-dimensional (3D) materials. However,…
Ferroelectric materials have remained one of the foci of condensed matter physics and materials science for over 50 years. In the last 20 years, the development of voltage-modulated scanning probe microscopy techniques, exemplified by…
The so-called interlayer-sliding ferroelectricity was recently proposed as an unconventional route to pursuit electric polarity in van der Waals multi-layers, which was already experimentally confirmed in WTe$_2$ bilayer even though it is…
Low-dimensional ferroelectricity and polar materials have attracted considerable attentions for their fascinating physics and potential applications. Based on first-principles calculations, here we investigate the stacking modes and polar…
The ground-state structure of monolayers and nanoplatelets of SnS with a thickness from two to five monolayers is calculated from first principles. It is shown that nanoobjects with only odd number of monolayers are ferroelectric. The…
Ferroelectric and two-dimensional materials are both heavily investigated classes of electronic materials. This is unsurprising since they both have superlative fundamental properties and high-value applications in computing, sensing etc.…
Sliding ferroelectricity was originally proposed to elucidate the out-of-plane polarization generated by a specific stacking arrangement of non-polar van der Waals layers. However, the concept of sliding ferroelectricity can be generalized…
Two-dimensional van der Waals (2D vdW) materials that display ferromagnetism and piezoelectricity have received increased attention. Despite numerous 2D materials have so far been reported as ferromagnetic, developing an air stable and…
Ferroelectricity has a wide range of applications in functional electronics and is extremely important for the development of next-generation information storage technology, but it is difficult to achieve due to its special symmetry…
The discoveries of magnetism and ferroelectricity in 2D van der Waals (vdW) materials have brought important functionalities to the 2D materials family, and may trigger a revolution in next generation nanoelectronics and spintronics. In…
Ferroelectric materials are characterized by the presence of an electric dipole that can be reversed by application of an external electric field, a feature that is exploited in ferroelectric memories. All ferroelectrics are piezoelectric,…
Ferroelectricity is commonly understood in terms of dynamical charges, which represent the dipole moments generated by atomic displacements or the forces induced by electric fields. In ferroelectrics with a high degree of symmetry, the…
Sliding ferroelectricity is a phenomenon that arises from the insurgence of spontaneous electronic polarization perpendicular to the layers of two-dimensional (2D) systems upon the relative sliding of the atomic layer constituents. Because…
Dielectric nano-swithes made of the materials that exhibit piezoelectric and/or flexoelectric properties with significant electro-mechanical coupling are considered. In this case, a nonuniform strain field may locally break inversion…
We study the role of electronegativity in sliding friction for five different two dimensional (2D) monolayer systems using density functional theory (DFT) with van der Waals (vdW) corrections. We show that the friction between the…
Surprising asymmetry in the local electromechanical response across a single antiparallel ferroelectric domain wall is reported. Piezoelectric force microscopy is used to investigate both the in-plane and out-of- plane electromechanical…