Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure tr...Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.展开更多
The increasing demand for resources and depletion of near ground mineral resources caused deeper mining operations under highstress rock mass conditions.As a result of this,strain burst,which is the sudden release of ...The increasing demand for resources and depletion of near ground mineral resources caused deeper mining operations under highstress rock mass conditions.As a result of this,strain burst,which is the sudden release of stored strain energy in the surrounding rock mass,has become more prevalent and created a considerable threat to workers and construction equipment.It is,therefore,imperative to understand how strain burst mechanism and stored excess strain energy are affected due to the high confinement in deep underground conditions.For this purpose,post-peak energy distributions for brittle rocks were investigated using a newly developed energy calculation method associated with acoustic emission(AE).A series of quasi-static uniaxial and triaxial compression tests controlled by the circumferential expansion were conducted.Snap-back behaviour known as Class-II behaviour associated with energy evolution and the material response under self-sustaining failure were analysed on granites under a wide range of confining pressures(0–60 MPa).The experimental results underline that the energy evolution characteristics are strongly linked to confinement.Stored elastic strain energy(dUE),energy consumed by dominating cohesion weakening(dUCW)and energy dissipated during mobilisation of frictional failure(dUFM)showed a rising trend as the confining pressure was increased.An intrinsic ejection velocity was proposed to express the propensity of strain burst that was purely determined by the excess strain energy released from Class II rock.展开更多
Strain engineering is a promising method for tuning the electronic properties of two-dimensional(2 D)materials,which are capable of sustaining enormous strain thanks to their atomic thinness.However,applying a large a...Strain engineering is a promising method for tuning the electronic properties of two-dimensional(2 D)materials,which are capable of sustaining enormous strain thanks to their atomic thinness.However,applying a large and homogeneous strain on these 2D materials,including the typical semiconductor MoS_(2),remains cumbersome.Here we report a facile strategy for the fabrication of highly strained MoS_(2) via chalcogenide substitution reaction(CSR)of MoTe_(2) with lattice inheritance.The MoS_(2)resulting from the sulfurized MoTe_(2) sustains ultra large in-plane strain(approaching its strength limit~10%)with great homogeneity.Furthermore,the strain can be deterministically and continuously tuned to~1.5%by simply varying the processing temperature.Thanks to the fine control of our CSR process,we demonstrate a heterostructure of strained MoS_(2)/MoTe_(2)with abrupt interface.Finally,we verify that such a large strain potentially allows the modulation of MoS_(2) bandgap over an ultra-broad range(~1 e V).Our controllable CSR strategy paves the way for the fabrication of highly strained 2D materials for applications in devices.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 61264008,61574080 and 61505085
文摘Regulation of optical properties and electronic structure of two-dimensionM layered ReS2 materials has attracted much attention due to their potential in electronic devices. However, the identification of structure transformation of monolayer ReS2 induced by strain is greatly lacking. In this work, the Raman spectra of monolayer ReS2 with external strain are determined theoretically based on the density function theory. Due to the lower structural symmetry, deformation induced by external strain can only regulate the Raman mode intensity but cannot lead to Raman mode shifts. Our calculations suggest that structural deformation induced by external strain can be identified by Raman scattering.
基金The authors gratefully acknowledge the financial support from the Australian Research Council(ARC)(ARC-LP150100539)OZ Minerals,and the principal geotechnical manager David Goodchild.The authors also wish to thank the laboratory technicians Adam Ryntjes and Simon Golding.
文摘The increasing demand for resources and depletion of near ground mineral resources caused deeper mining operations under highstress rock mass conditions.As a result of this,strain burst,which is the sudden release of stored strain energy in the surrounding rock mass,has become more prevalent and created a considerable threat to workers and construction equipment.It is,therefore,imperative to understand how strain burst mechanism and stored excess strain energy are affected due to the high confinement in deep underground conditions.For this purpose,post-peak energy distributions for brittle rocks were investigated using a newly developed energy calculation method associated with acoustic emission(AE).A series of quasi-static uniaxial and triaxial compression tests controlled by the circumferential expansion were conducted.Snap-back behaviour known as Class-II behaviour associated with energy evolution and the material response under self-sustaining failure were analysed on granites under a wide range of confining pressures(0–60 MPa).The experimental results underline that the energy evolution characteristics are strongly linked to confinement.Stored elastic strain energy(dUE),energy consumed by dominating cohesion weakening(dUCW)and energy dissipated during mobilisation of frictional failure(dUFM)showed a rising trend as the confining pressure was increased.An intrinsic ejection velocity was proposed to express the propensity of strain burst that was purely determined by the excess strain energy released from Class II rock.
基金supported by the National Natural Science Foundation of China(21825103,52001165)Natural Science Foundation of Hubei Province(2019CFA002)+2 种基金Natural Science Foundation of Jiangsu Province(BK20200475)the Fundamental Research Funds for the Central Universities(2019kfy XMBZ018,30921011215)supports from Analytical and Testing Center in Huazhong University of Science and Technology as well as Nanostructure Research Center(NRC)supported by the Fundamental Research Funds for the Central Universities(WUT:2019III012GX,2020III002GX)。
文摘Strain engineering is a promising method for tuning the electronic properties of two-dimensional(2 D)materials,which are capable of sustaining enormous strain thanks to their atomic thinness.However,applying a large and homogeneous strain on these 2D materials,including the typical semiconductor MoS_(2),remains cumbersome.Here we report a facile strategy for the fabrication of highly strained MoS_(2) via chalcogenide substitution reaction(CSR)of MoTe_(2) with lattice inheritance.The MoS_(2)resulting from the sulfurized MoTe_(2) sustains ultra large in-plane strain(approaching its strength limit~10%)with great homogeneity.Furthermore,the strain can be deterministically and continuously tuned to~1.5%by simply varying the processing temperature.Thanks to the fine control of our CSR process,we demonstrate a heterostructure of strained MoS_(2)/MoTe_(2)with abrupt interface.Finally,we verify that such a large strain potentially allows the modulation of MoS_(2) bandgap over an ultra-broad range(~1 e V).Our controllable CSR strategy paves the way for the fabrication of highly strained 2D materials for applications in devices.
