相关论文: Cyclic Ferroelectric Switching and Quantized Charg…
Ferroelectrics that are also ionic conductors offer possibilities for novel applications with high tunability, especially if the same atomic species causes both phenomena. In particular, at temperatures just below the Curie temperature,…
The van der Waals layered material CuInP2S6 features interesting functional behavior, including the existence of four uniaxial polarization states, polarization reversal against the electric field through Cu ion migration, a…
The switching dynamics of ferroelectric materials is a crucial intrinsic property which directly affects the operation and performance of ferroelectric devices. In conventional ferroelectric materials, the typical ferroelectric switching…
We consider nanoflakes of van der Waals ferrielectric CuInP$_2$S$_6$ covered by an ionic surface charge and reveal the appearance of polar states with relatively high polarization ~5 microC/cm$^2$ and stored free charge ~10 microC/cm$%2$,…
Interlayer stacking order has recently emerged as a unique degree of freedom to control crystal symmetry and physical properties in two-dimensional van der Waals (vdW) materials and heterostructures. By tuning the layer stacking pattern,…
Using first-principles calculations we model the out-of-plane switching of local dipoles in CuInP$_2$S$_6$ (CIPS) that are largely induced by Cu off-centering. Previously, a coherent switching of polarization via a quadruple-well potential…
Copper indium thiophosphate, CuInP2S6, has attracted much attention in recent years due to its van der Waals layered structure and robust ferroelectricity at room temperature. In this review, we aim to give an overview of the various…
As a layered ferroelectric material, CuInP2S6 has garnered significant attention for its robust ferroelectric state and potential applications in memory devices. In this work, we demonstrate that with short laser pulses ultrafast reversible…
Van der Waals (vdW) layered materials have rather weaker interlayer bonding than the intra-layer bonding, therefore the exfoliation along the stacking direction enables the achievement of monolayer or few layers vdW materials with emerging…
Ferroelectricity in atomically thin bilayer structures has been recently predicted1 and measured[2-4] in two-dimensional (2D) materials with hexagonal non-centrosymmetric unit-cells. Interestingly, the crystal symmetry translates lateral…
Using DFT-based molecular dynamics simulation of Cu$^+$ cations flipping and In$^{3+}$ cations displacive dynamics, we clarify the dipole ordering of CuInP$_2$S$_6$ ferrielectrics through the second order Jahn-Teller effect which determines…
The appearance of spontaneous polarization in CuInP$_{2}$S$_{6}$ ferrielectrics is related to the second order Jahn-Teller effect for copper cations located in a double-well local potential, the stereoactivity of indium cations located in a…
The bistability of charge polarization in ferroelectric materials has long been the basis of ferroelectric devices. However, the ferroelectricity tends to be vanishing as the thickness of materials is reduced to a few nanometers or thinner…
Van der Waals (vdW) polytypes of broken inversion and mirror symmetries were recently shown to exhibit switchable electric polarization even at the ultimate two-layer thin limit. Their out-of-plane polarization was found to accumulate in a…
When the atomic layers in a non-centrosymmetric van der Waals structure slide against each other, the interfacial charge transfer results in a reversal of the structures spontaneous polarization. This phenomenon is known as sliding…
CuInP2S6 (CIPS) is an emerging layered material that exhibits ferrielectric ordering well above room temperature (Curie temperature TC ~ 315 K). When synthesized with Cu deficiencies, CIPS spontaneously segregates into CuInP2S6 and…
Layered multi-ferroic materials exhibit a variety of functional properties that can be tuned by varying the temperature and pressure. As-synthesized CuInP$_2$S$_6$ is a layered material that displays ferrielectric behavior at room…
Low-dimensional multiferroicity, though highly scarce in nature, has attracted great attention due to both fundamental and technological interests. Using first-principles density functional theory, we show that ferromagnetism and…
Out-of-plane and in-plane electric polarization, which rarely coexist in a two-dimensional (2D) ferroelectric material, offer different advantages in ferroelectricity-based devices. Here, we report the coexistence of in-plane and…
Ferroelectric van der Waals CuInP$_2$S$_6$ possesses intriguing quadruple-well states and negative piezoelectricity. Its technological implementation has been impeded by the relatively low Curie temperature (bulk $T_C$ ~42 {\deg}C) and the…