We theoretically investigate the mechanism of ferroelectric switching via interlayer shear in 3R MoS using first principles and lattice dynamics calculations. First principle calculations show the prominent anharmonic coupling of the infrared inactive interlayer shear and the infrared active phonons. The nonlinear coupling terms generates an effective anharmonic force which drives the interlayer shear mode and lowers the ferroelectric switching barrier depending on the amplitude and polarization of infrared mode. Lattice dynamics simulations show that the interlayer shear mode can be coherently excited to the switching threshold by a train of infrared pulses polarized along the zigzag axis of MoS. The results of this study indicate the possibility of ultrafast ferroelectricity in stacked two-dimensional materials from the control of stacking sequence.
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http://dx.doi.org/10.1038/s41598-019-50293-y | DOI Listing |
Biomimetics (Basel)
December 2024
Heilongjiang Construction Investment Group Co., Ltd., Harbin 150046, China.
The bio-inspired honeycomb column thin-walled structure (BHTS) is inspired by the biological structure of beetle elytra and designed as a lightweight buffer interlayer to prevent damage to the reinforced concrete bridge pier (RCBP) under the overload impact from vehicle impact. According to the prototype structure of the pier, a batch of scale models with a scaling factor of 1:10 was produced. The BHTS buffer interlayer was installed on the reinforced concrete (RC) column specimen to carry out the steel ball impact test.
View Article and Find Full Text PDFGels
December 2024
School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan 316022, China.
Long-term polymer flooding exacerbates reservoir heterogeneity, intensifying intra- and inter-layer conflicts, which makes it difficult to recover the remaining oil. Therefore, further improvement in oil recovery after polymer flooding is essential. In this study, a weak gel system was successfully synthesized, and possesses a distinct network structure that becomes more compact as the concentration of partially hydrolyzed polyacrylamide increases.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
The unique layer-stacking in two-dimensional (2D) van der Waals materials facilitates the formation of nearly degenerate phases of matter and opens novel routes for the design of low-power, reconfigurable functional materials. Electrochemical ion intercalation between stacked layers offers a promising approach to stabilize bulk metastable phases and to explore the effects of extreme carrier doping and strain. However, in situ characterization methods to study the structural evolution and dynamical functional properties of these intercalated materials remains limited.
View Article and Find Full Text PDFNanoscale
December 2024
Boston University, Department of Mechanical Engineering, Boston, MA 02215, USA.
We measure the out-of-plane shear modulus of few-layer graphene (FLG) by a blister test. During the test, we employed a monolayer molybdenum disulfide (MoS) membrane stacked onto FLG wells to facilitate the separation of FLG from the silicon oxide (SiO) substrate. Using the deflection profile of the blister, we determine an average shear modulus of 0.
View Article and Find Full Text PDFUltrason Sonochem
November 2024
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, PR China. Electronic address:
Ceramic coatings containing two-dimensional materials (2D materials) provide effective protection for light alloys during wear, significantly improving their anti-friction performance. MoS has proven highly effective in enhancing the anti-friction performance of ceramic coatings, particularly when synthesized via plasma electrolytic oxidation (PEO). However, dislocation pinning due to the incoherent interfaces in MoS/TiO coatings tends to cause localized stress concentrations and brittle fracture, requiring effectively improve nanomechanical properties by optimizing interface design.
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