When the size of a magneto-electro-elastic cylindrical shell (MEECS) is reduced to micro-/nano-scale, the size-dependent flexomagnetic effect (FME) and flexoelectric effect (FEE) significantly influence their multi-ph...When the size of a magneto-electro-elastic cylindrical shell (MEECS) is reduced to micro-/nano-scale, the size-dependent flexomagnetic effect (FME) and flexoelectric effect (FEE) significantly influence their multi-physical coupling behaviors. To investigate these effects on the post-buckling behaviors of an MEECS, a nonlinear post-buckling model is developed based on the higher-order shear deformation theory (HSDT) and magneto-electro-elastic (MEE) constitutive relations with the FME and FEE. The equilibrium path and the corresponding shell deformations are obtained with a set of newly developed generalized displacement functions within the framework of the Galerkin approach. These displacement functions are established based on the trigonometric series expansions, which accurately satisfy the clamped boundary conditions (BCs). The effects of geometry, flexomagnetic/flexoelectric coefficients, and external electromagnetic fields on the post-buckling behaviors of an MEECS with the FME and FEE are analyzed. Numerical results indicate that the FME decreases the upper critical load of an MEECS, whereas the FEE exhibits an opposite effect by increasing it.展开更多
This research utilizes analytical solutions to investigate the issue of nonlinear static bending in nanobeams affected by the flexomagnetic effect.The nanobeams are exposed to mechanical loads and put in a temperature...This research utilizes analytical solutions to investigate the issue of nonlinear static bending in nanobeams affected by the flexomagnetic effect.The nanobeams are exposed to mechanical loads and put in a temperature environment.The equilibrium equation of the beam is formulated based on the newly developed higher-order shear deformation theory.The flexomagnetic effect is explained by the presence of the strain gradient component,which also takes into consideration the impact of small-size effects.This study has used a flexible transformation to derive the equilibrium equation for a single variable,which significantly simplifies the process of determining the precise solution to the bending issue.This highlights the originality and significance of the present study,which is based on a newly developed shear deformation theory to clarify the distinctions between the nonlinear and linear problems.This study also presents the findings of numerical simulations that investigate the impact of various geometric,material,and temperature parameters on the nonlinear behavior of nanobeams.These discoveries are significant for designers to develop nanobeams that can function efficiently in many physical conditions,including mechanical,thermal,and magnetic mediums.展开更多
Strain gradient is a normal phenomenon around a heterostructural interface in ultrathin film,and it is important to determine its effect on magnetic interactions to understand interfacial coupling.In this work,ultrath...Strain gradient is a normal phenomenon around a heterostructural interface in ultrathin film,and it is important to determine its effect on magnetic interactions to understand interfacial coupling.In this work,ultrathin Pr_(0.67)Sr_(0.33)MnO_(3)(PSMO)films on different substrates are studied.For PSMO film under different in-plane strain conditions,the saturated magnetization and Curie temperature can be qualitatively explained by double-exchange interaction and the Jahn-Teller distortion.However,the difference in the saturated magnetization with zero field cooling and 5 T field cooling is proportional to the strain gradient.Strain-gradient-induced structural disorder is proposed to enhance phonon-electron antiferromagnetic interactions and the corresponding antiferromagnetic-to-ferromagnetic phase transition via a strong magnetic field during the field cooling process.A non-monotonous structural transition of the MnO_(6) octahedral rotation can enlarge the strain gradient in PSMO film on a SrTiO_(3) substrate.This work demonstrates the existence of the flexomagnetic effect in ultrathin manganite film,which should be applicable to other complex oxide systems.展开更多
Flexoelectric effect describes the electromechanical coupling between the strain gradient and its internal polarization in all dielectrics.Despite this universality,the resulting flexoelectric field remains small at t...Flexoelectric effect describes the electromechanical coupling between the strain gradient and its internal polarization in all dielectrics.Despite this universality,the resulting flexoelectric field remains small at the macroscopic level.However,in nanosystems,the size-dependent effect of flexoelectricity becomes increasingly significant,leading to a notable flexoelectric field that can strongly influence the material’s physical properties.This review aims to explore the flexoelectric effect specifically at the nanoscale.We achieve this by examining strain gradients generated through two distinct methods:internal inhomogeneous strain and external stimulation.In addition,advanced synthesis techniques are utilized to enhance the properties and functionalities associated with flexoelectricity.Furthermore,we delve into other coupled phenomena observed in thin films,including the coupling and utilization of flexomagnetic and flexophotovoltaic effects.This review presents the latest advancements in these areas and highlights their role in driving further breakthroughs in the field of flexoelectricity.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 12472064)。
文摘When the size of a magneto-electro-elastic cylindrical shell (MEECS) is reduced to micro-/nano-scale, the size-dependent flexomagnetic effect (FME) and flexoelectric effect (FEE) significantly influence their multi-physical coupling behaviors. To investigate these effects on the post-buckling behaviors of an MEECS, a nonlinear post-buckling model is developed based on the higher-order shear deformation theory (HSDT) and magneto-electro-elastic (MEE) constitutive relations with the FME and FEE. The equilibrium path and the corresponding shell deformations are obtained with a set of newly developed generalized displacement functions within the framework of the Galerkin approach. These displacement functions are established based on the trigonometric series expansions, which accurately satisfy the clamped boundary conditions (BCs). The effects of geometry, flexomagnetic/flexoelectric coefficients, and external electromagnetic fields on the post-buckling behaviors of an MEECS with the FME and FEE are analyzed. Numerical results indicate that the FME decreases the upper critical load of an MEECS, whereas the FEE exhibits an opposite effect by increasing it.
文摘This research utilizes analytical solutions to investigate the issue of nonlinear static bending in nanobeams affected by the flexomagnetic effect.The nanobeams are exposed to mechanical loads and put in a temperature environment.The equilibrium equation of the beam is formulated based on the newly developed higher-order shear deformation theory.The flexomagnetic effect is explained by the presence of the strain gradient component,which also takes into consideration the impact of small-size effects.This study has used a flexible transformation to derive the equilibrium equation for a single variable,which significantly simplifies the process of determining the precise solution to the bending issue.This highlights the originality and significance of the present study,which is based on a newly developed shear deformation theory to clarify the distinctions between the nonlinear and linear problems.This study also presents the findings of numerical simulations that investigate the impact of various geometric,material,and temperature parameters on the nonlinear behavior of nanobeams.These discoveries are significant for designers to develop nanobeams that can function efficiently in many physical conditions,including mechanical,thermal,and magnetic mediums.
基金supported by the Natural Science Foundation of Guangdong Province of China(2023A1515010882)the Large Scientific Facility Open Subject of Songshan Lake,Dongguan,Guangdong Province of China(KFKT2022B06)+2 种基金the Singapore Ministry of Education Academic Research Fund Tier 2(MOE2015-T2-1-016,MOE2018-T2-1-019,and MoE T1 R-284-000-196-114)the Singapore National Research Foundation(NRF-CRP10-2012-02)supported from SSLS via National University of Singapore Core Support(C-380-003-003-001).
文摘Strain gradient is a normal phenomenon around a heterostructural interface in ultrathin film,and it is important to determine its effect on magnetic interactions to understand interfacial coupling.In this work,ultrathin Pr_(0.67)Sr_(0.33)MnO_(3)(PSMO)films on different substrates are studied.For PSMO film under different in-plane strain conditions,the saturated magnetization and Curie temperature can be qualitatively explained by double-exchange interaction and the Jahn-Teller distortion.However,the difference in the saturated magnetization with zero field cooling and 5 T field cooling is proportional to the strain gradient.Strain-gradient-induced structural disorder is proposed to enhance phonon-electron antiferromagnetic interactions and the corresponding antiferromagnetic-to-ferromagnetic phase transition via a strong magnetic field during the field cooling process.A non-monotonous structural transition of the MnO_(6) octahedral rotation can enlarge the strain gradient in PSMO film on a SrTiO_(3) substrate.This work demonstrates the existence of the flexomagnetic effect in ultrathin manganite film,which should be applicable to other complex oxide systems.
基金supported by the National Natural Science Foundation of China(Nos.51962020,12174174)Support from the Natural Science Foundation of Jiangxi Province(No.20212ACB214011)was also acknowledged.
文摘Flexoelectric effect describes the electromechanical coupling between the strain gradient and its internal polarization in all dielectrics.Despite this universality,the resulting flexoelectric field remains small at the macroscopic level.However,in nanosystems,the size-dependent effect of flexoelectricity becomes increasingly significant,leading to a notable flexoelectric field that can strongly influence the material’s physical properties.This review aims to explore the flexoelectric effect specifically at the nanoscale.We achieve this by examining strain gradients generated through two distinct methods:internal inhomogeneous strain and external stimulation.In addition,advanced synthesis techniques are utilized to enhance the properties and functionalities associated with flexoelectricity.Furthermore,we delve into other coupled phenomena observed in thin films,including the coupling and utilization of flexomagnetic and flexophotovoltaic effects.This review presents the latest advancements in these areas and highlights their role in driving further breakthroughs in the field of flexoelectricity.
