Shape Anisotropy(形状各向异性)研究综述
Shape Anisotropy 形状各向异性 - The concept of Perpendicular Shape Anisotropy (PSA) spin transfer torque (STT) MRAM has been recently proposed as a solution to achieve downsize scalability of MRAM below sub-10 nm technology nodes, down to 3–4 nm cell size lateral dimensions. [1] We outline advances and challenges in controlling particle properties through varying shape anisotropy and surface asymmetry. [2] Our results emphasise the importance of considering the initial magmatic microstructures and the original shape anisotropy when investigating later deformation in ultramafic rocks. [3] However, the effects of shape anisotropy on the settling dynamics of a particle in a stratified fluid are not completely understood. [4] The size of diameter is consistent with the AAO template pores and the FeCo and CoFe2O4 nanowire arrays have a large aspect ratio and shape anisotropy. [5] This change in domain structure as strip width decreases is consistent with both the influence of shape anisotropy and with measurements of magnetic hysteresis. [6] The experimentally realized structural color exhibits a wide color gamut covering the whole cyan, magenta, and yellow (CMY) color system, and presents a strong dependence on the incident polarization state due to its shape anisotropy. [7] After excluding the general absorption mechanisms, including conductive losses, interfacial polarization, and dipole polarization, the distinctive single-crystal volume polarization affected by shape anisotropy was proposed. [8] In addition, the anisotropy of the grooved films can be also tuned through the shape anisotropy of the gratings. [9] In this context, the role of symmetry/shape anisotropy of both the nanomaterials and the biological interfaces on their interaction mechanism, is a relatively unaddressed issue. [10] The recent developments in data acquisition and evaluation allow the accurate determination of particle size, shape anisotropy and particle density. [11] Co nanowires exhibit a high coercive field H c , shape anisotropy, and squareness ratio M M s than those corresponding to Ni nanowires. [12] The rotational hydrodynamics of nanoparticles is measured and considered under the influence of magnetic shape anisotropy in the framework of the Stoner-Wohlfarth theory. [13] To study the effect of shape of the sample, we have varied the aspect ratio Ar = Ly/Lx which in turn, is found to induce shape anisotropy in the system. [14] The competition between magnetic shape anisotropy and the induced uniaxial magnetic anisotropy in the heterojunction between a ferromagnetic layer and a ferroelectric substrate serves to control magnetic domain structures as well as magnetization reversal characteristics. [15] α″-Fe16N2 nanomaterials with a shape anisotropy for high coercivity performance are of interest in potential applications such as rare-earth-free permanent magnets, which are difficult to synthesize in situ anisotropic growth. [16] A striped domain structure is formed in the Ni wires that is aligned perpendicular to the X-axis of the LiNbO3 substrate owing to the competition between magnetic shape anisotropy and uniaxial magnetic anisotropy from the heterojunction. [17] Enhancement in microwave absorption feature predominantly depend on different factors such as multiple internal reflections between layers, interfacial polarization, phase cancellations, conduction loss, shape anisotropy and so on. [18] This system can efficiently serve as a magnonic crystal (MC), where the intrinsic shape anisotropy and the strong inter-element magnetostatic interaction trigger the incoherent precession of the nanomagnets' magnetization in the absence of any bias magnetic field, giving rise to the 'intrinsic' SW modes. [19] Because of the shape anisotropy of the columnar structure, the coercivity of the parallel magnetic field increased, whereas the coercivity of the perpendicular magnetic field decreased. [20] Moreover, we also briefly discussed the importance of magnetoshape anisotropy related to particle design aspect of magnetophoretic systems. [21] However, those simplifications do not work for more complex systems with domain walls, shape anisotropy or exchange-bias. [22] Using the Parsons-Lee theory, we examined the effect of shape anisotropy and the wall-to-wall separation (H) on the phase behavior of the hard parallelepiped rods with dimensions L, D, and D (L>D) in such narrow slitlike pores which only one homeotropic layer can form. [23] Shape anisotropy of active materials mainly determines the sensitivity of magneto-optic response, thereby making magnetic two-dimensional (2D) materials suitable in achieving the giant magneto-birefringence effect as discovered recently. [24] The joint effect of boundary conditions, cell shape anisotropy, swimming speed, and flow speed leads to the nonmonotonic variations of the phenomenological dispersion coefficients. [25] Compared with the bulk counterpart, significantly increased surface area, conductivity, and shape anisotropy for the 2D derivatives result in enhanced interfacial polarization, conductive loss, and magnetic resonance. [26] It results in a substantial reduction in harmonics errors due to the dispersion of the shape anisotropy field values within each element. [27] The shape anisotropy of γ1 and γ2, the concentration of Fe, Co, Ni in the γ2 phase, and the content of the α phase are the main factors to determine the magnetic properties. [28] It is suggested that, tilt of the easy axis can be understood in terms of the interplay of two shape anisotropy terms corresponding to the ensemble of strongly interacting nanocolumns through magnetostatic dipolar interaction, and the overall shape of a nanowire. [29] It can be assumed that such beads will support domain wall formation due to a reduction of the relative impact of the shape anisotropy, in this way influencing magnetization reversal along the fiber. [30] An alternative concept based on perpendicular shape anisotropy (PSA) can also yield a reduction by 1–2 orders of magnitude in these quantities. [31] Herein, we report a method to control the shape anisotropy of monoclinic Nb12O29 nanocrystals and obtain a tunable electrochromic spectral range. [32] The results indicate that the relative Young’s modulus and relative yield strength decrease with the increasing characteristic diameter Dch and characteristic shape anisotropy αch. [33] Depending on the level of cell shape anisotropy or the strength of the polarity domain, one dominates the other and determines the orientation of the spindle. [34] In this context, the role of symmetry/shape anisotropy of both the nanomaterials and biological interfaces in their mutual interaction, is a relatively unaddressed issue. [35] Due to the strong impact of shape anisotropy in nanostructures, the magnetization-reversal process including coercive and reversibility fields can be expected to be different in concave or convex superellipses than that in common squares. [36] FeSi flakes with high diameter possess higher permittivity for the larger specific areas and higher permeability for the increased shape anisotropy. [37] Through a comprehensive Monte Carlo investigation, this study demonstrates how the mechanical properties of self‐assembled magnetic nanocubes can be controlled intrinsically by the nanoparticle magnetocrystalline anisotropy (MA), as well as by the superstructure shape anisotropy, without any need for changes in structural design (i. [38] Taking a realistic experimental geometry of magnetic thin films, nanowires and nanodiscs, magnon eigenfrequencies, eigenvectors and Q-factors are found to depend on the shape anisotropy. [39] We reported microwave measurements on a nanoscale MgO-based magnetic tunnel junction having an elliptical shape with large aspect ratios to obtain enough in-plane shape anisotropy to ensure free layer magnetization along the long axis. [40] These 1-D structures introduce a pronounced shape anisotropy that together with material selection can strongly affect the magnetic properties and can be tuned by incorporating segments of different materials or diameters along the length. [41] It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. [42] Here, we show the effect of the body-shape anisotropy of the microrollers on their locomotion capability over vessel-like microtopographies. [43] We use two systems and employ two different approaches exploiting shape anisotropy or polarization memory of individual units for control of the persistence length. [44] In this letter, we demonstrate that this behavior can be implemented in DW-MTJ artificial neurons via three alternative mechanisms: shape anisotropy, magnetic field, and current-driven soft reset. [45] The magnetic peculiarities of thin film grown at 20 ° C can be explained by the competing influence of the dipolar interactions and shape anisotropy of vertically elongated grains, and the presence of intergranular soft magnetic material. [46] The angular magnetic switching originates from competition among the E-field-induced magnetoelastic anisotropy, magnetic shape anisotropy, and Zeeman energy, which is confirmed by micromagnetic simulations. [47] In contrast to pseudo periodic boundary conditions, which are widely used in micromagnetic codes, the presented methods eliminate the shape anisotropy originating from the outer boundary. [48] This work provides a theoretical framework for understanding the behaviors of rodlike colloids in ferrofluids and highlights the importance of shape anisotropy in manipulating colloids and their self-assembly. [49] The controllable complex emulsions by electricity present a versatile platform for constructing fine control of the microstructure and shape anisotropy of particles having customized shapes and functionalities, opening a new possibility for designing sophisticated architectures. [50]垂直形状各向异性 (PSA) 自旋转移矩 (STT) MRAM 的概念最近被提出作为一种解决方案，以实现低于 10 纳米技术节点的 MRAM 尺寸可扩展性，低至 3-4 纳米单元尺寸横向尺寸。 [1] 我们概述了通过改变形状各向异性和表面不对称性来控制粒子特性的进展和挑战。 [2] 我们的结果强调了在研究超镁铁质岩石后期变形时考虑初始岩浆微结构和原始形状各向异性的重要性。 [3] 然而，形状各向异性对分层流体中颗粒沉降动力学的影响尚不完全清楚。 [4] 直径大小与AAO模板孔一致，FeCo和CoFe2O4纳米线阵列具有较大的纵横比和形状各向异性。 [5] 随着条带宽度减小，畴结构的这种变化与形状各向异性的影响和磁滞的测量结果一致。 [6] 实验实现的结构色具有覆盖整个青色、品红色和黄色（CMY）颜色系统的宽色域，并且由于其形状各向异性而对入射偏振态具有很强的依赖性。 [7] 在排除了包括导电损耗、界面极化和偶极极化在内的一般吸收机制后，提出了受形状各向异性影响的独特单晶体极化。 [8] 此外，还可以通过光栅的形状各向异性来调节刻槽薄膜的各向异性。 [9] 在这种情况下，纳米材料和生物界面的对称性/形状各向异性对其相互作用机制的作用是一个相对未解决的问题。 [10] 数据采集和评估方面的最新发展允许准确测定颗粒尺寸、形状各向异性和颗粒密度。 [11] 与对应于Ni纳米线的那些相比，Co纳米线表现出高矫顽场H c 、形状各向异性和矩形比M M s 。 [12] 在 Stoner-Wohlfarth 理论的框架内，在磁性形状各向异性的影响下测量和考虑纳米粒子的旋转流体动力学。 [13] 为了研究样品形状的影响，我们改变了纵横比 Ar = Ly/Lx，这反过来又会导致系统中的形状各向异性。 [14] 在铁磁层和铁电衬底之间的异质结中，磁形状各向异性和诱导的单轴磁各向异性之间的竞争用于控制磁畴结构以及磁化反转特性。 [15] 具有高矫顽力性能的形状各向异性的 α″-Fe16N2 纳米材料在难以合成原位各向异性生长的无稀土永磁体等潜在应用中受到关注。 [16] 由于异质结的磁性形状各向异性和单轴磁性各向异性之间的竞争，在垂直于 LiNbO3 衬底的 X 轴排列的 Ni 线中形成了条状畴结构。 [17] 微波吸收特性的增强主要取决于不同的因素，例如层间的多次内反射、界面极化、相位抵消、传导损耗、形状各向异性等。 [18] 该系统可以有效地用作磁子晶体（MC），其中固有的形状各向异性和强的元素间静磁相互作用在没有任何偏置磁场的情况下触发纳米磁体磁化的非相干进动，从而产生“本征” ' 软件模式。 [19] 由于柱状结构的形状各向异性，平行磁场的矫顽力增加，而垂直磁场的矫顽力降低。 [20] 此外，我们还简要讨论了与磁泳系统的粒子设计相关的磁形状各向异性的重要性。 [21] 然而，这些简化不适用于具有畴壁、形状各向异性或交换偏置的更复杂的系统。 [22] 使用 Parsons-Lee 理论，我们研究了形状各向异性和壁间分离 (H) 对尺寸为 L、D 和 D (L>D) 的硬平行六面体棒的相行为的影响。只能形成一层垂直层的狭缝状孔隙。 [23] 活性材料的形状各向异性主要决定了磁光响应的灵敏度，从而使磁性二维（2D）材料适用于实现最近发现的巨磁双折射效应。 [24] 边界条件、细胞形状各向异性、游泳速度和流速的共同作用导致了唯象色散系数的非单调变化。 [25] 与块体对应物相比，2D 衍生物的表面积、电导率和形状各向异性显着增加，导致界面极化、传导损耗和磁共振增强。 [26] 由于每个元素内形状各向异性场值的分散，它会显着减少谐波误差。 [27] γ1和γ2的形状各向异性、γ2相中Fe、Co、Ni的浓度以及α相的含量是决定磁性能的主要因素。 [28] 有人建议，易轴的倾斜可以根据两个形状各向异性项的相互作用来理解，这两个形状各向异性项对应于通过静磁偶极相互作用强相互作用的纳米柱的集合，以及纳米线的整体形状。 [29] 可以假设，由于形状各向异性的相对影响减少，这种珠子将支持畴壁形成，从而影响沿纤维的磁化反转。 [30] 基于垂直形状各向异性 (PSA) 的替代概念也可以使这些数量减少 1-2 个数量级。 [31] 在此，我们报告了一种控制单斜 Nb12O29 纳米晶体的形状各向异性并获得可调电致变色光谱范围的方法。 [32] 结果表明，相对杨氏模量和相对屈服强度随着特征直径Dch和特征形状各向异性αch的增加而降低。 [33] 根据细胞形状各向异性的水平或极性域的强度，一个支配另一个并决定了纺锤体的方向。 [34] 在这种情况下，纳米材料和生物界面的对称性/形状各向异性在它们相互作用中的作用是一个相对未解决的问题。 [35] 由于纳米结构中形状各向异性的强烈影响，包括矫顽力和可逆性场在内的磁化反转过程可以预期在凹形或凸形超椭圆中与普通正方形中的不同。 [36] 具有大直径的 FeSi 薄片对于较大的比面积具有较高的介电常数，对于增加的形状各向异性具有较高的磁导率。 [37] 通过全面的蒙特卡罗研究，本研究证明了自组装磁性纳米立方体的机械性能如何可以通过纳米颗粒磁晶各向异性 (MA) 以及上层结构形状各向异性来控制，而无需改变结构设计（一世。 [38] 以磁性薄膜、纳米线和纳米盘的真实实验几何形状为例，发现磁振子特征频率、特征向量和 Q 因子取决于形状各向异性。 [39] 我们报道了对纳米级 MgO 基磁性隧道结的微波测量，该磁性隧道结具有大纵横比的椭圆形状，以获得足够的面内形状各向异性，以确保沿长轴的自由层磁化。 [40] 这些一维结构引入了明显的形状各向异性，与材料选择一起可以强烈影响磁性，并且可以通过沿长度结合不同材料或直径的段来进行调整。 [41] 结果表明，偶极相互作用改变了镍纳米线反向磁化过程中的退磁场，以及静磁单轴形状各向异性的一般有效场。 [42] 在这里，我们展示了微滚轮的体形各向异性对其在血管状微拓扑结构上的运动能力的影响。 [43] 我们使用两个系统并采用两种不同的方法，利用单个单元的形状各向异性或偏振记忆来控制持久长度。 [44] 在这封信中，我们证明了这种行为可以通过三种替代机制在 DW-MTJ 人工神经元中实现：形状各向异性、磁场和电流驱动的软复位。 [45] 在 20°C 下生长的薄膜的磁性特性可以通过垂直拉长晶粒的偶极相互作用和形状各向异性的竞争影响以及晶间软磁材料的存在来解释。 [46] 角磁切换源于电场诱导的磁弹性各向异性、磁形状各向异性和塞曼能量之间的竞争，这已通过微磁模拟得到证实。 [47] 与在微磁代码中广泛使用的伪周期性边界条件相比，所提出的方法消除了源自外边界的形状各向异性。 [48] 这项工作为理解铁磁流体中棒状胶体的行为提供了一个理论框架，并强调了形状各向异性在操纵胶体及其自组装中的重要性。 [49] 电控复杂乳液为构建具有定制形状和功能的颗粒的微观结构和形状各向异性的精细控制提供了一个多功能平台，为设计复杂结构开辟了新的可能性。 [50]
Magnetic Shape Anisotropy
The rotational hydrodynamics of nanoparticles is measured and considered under the influence of magnetic shape anisotropy in the framework of the Stoner-Wohlfarth theory. [1] The competition between magnetic shape anisotropy and the induced uniaxial magnetic anisotropy in the heterojunction between a ferromagnetic layer and a ferroelectric substrate serves to control magnetic domain structures as well as magnetization reversal characteristics. [2] A striped domain structure is formed in the Ni wires that is aligned perpendicular to the X-axis of the LiNbO3 substrate owing to the competition between magnetic shape anisotropy and uniaxial magnetic anisotropy from the heterojunction. [3] The angular magnetic switching originates from competition among the E-field-induced magnetoelastic anisotropy, magnetic shape anisotropy, and Zeeman energy, which is confirmed by micromagnetic simulations. [4] In this thin film layer system cap, the magnetic shape anisotropy of the topographically non-flat hemispheres competes with the unidirectional anisotropy induced by the exchange bias. [5] The elements printed from selected composites exhibit weak but well pronounced magnetic shape anisotropy – a feature characteristic for bulk magnets. [6] The multilayered nanowires with the diameter ranging from 35 to 70 nm were spontaneously magnetized in the axial direction due to the preferential crystal orientation of hcp-Co (002) which was induced by the magnetic shape anisotropy. [7] This effect was observed because of changes to the magnetic shape anisotropy induced by the nano-imprinting. [8] Magnetic shape anisotropy is utilized to generate single body submillimeter magnetic microrobots capable of 6-DOF actuation. [9]在 Stoner-Wohlfarth 理论的框架内，在磁性形状各向异性的影响下测量和考虑纳米粒子的旋转流体动力学。 [1] 在铁磁层和铁电衬底之间的异质结中，磁形状各向异性和诱导的单轴磁各向异性之间的竞争用于控制磁畴结构以及磁化反转特性。 [2] 由于异质结的磁性形状各向异性和单轴磁性各向异性之间的竞争，在垂直于 LiNbO3 衬底的 X 轴排列的 Ni 线中形成了条状畴结构。 [3] 角磁切换源于电场诱导的磁弹性各向异性、磁形状各向异性和塞曼能量之间的竞争，这已通过微磁模拟得到证实。 [4] nan [5] nan [6] nan [7] nan [8] nan [9]
Perpendicular Shape Anisotropy
The concept of Perpendicular Shape Anisotropy (PSA) spin transfer torque (STT) MRAM has been recently proposed as a solution to achieve downsize scalability of MRAM below sub-10 nm technology nodes, down to 3–4 nm cell size lateral dimensions. [1] An alternative concept based on perpendicular shape anisotropy (PSA) can also yield a reduction by 1–2 orders of magnitude in these quantities. [2] Perpendicular shape anisotropy spin-transfer-torque magnetic random-access memory (PSA-STT-MRAM) demonstrates high thermal stability when size is reduced to 20 nm, which gives a new way to improve the integrity of electronic devices. [3] Magnetic tunneling junctions with strong perpendicular shape anisotropy attract attention due to their high-density magnetic random access memory. [4] Cylindrical magnetic nanowires, possessing high aspect ratio and outstanding perpendicular shape anisotropy, have been an excellent candidate for next generation perpendicular magnetic recording. [5]垂直形状各向异性 (PSA) 自旋转移矩 (STT) MRAM 的概念最近被提出作为一种解决方案，以实现低于 10 纳米技术节点的 MRAM 尺寸可扩展性，低至 3-4 纳米单元尺寸横向尺寸。 [1] 基于垂直形状各向异性 (PSA) 的替代概念也可以使这些数量减少 1-2 个数量级。 [2] nan [3] nan [4] nan [5]
Increased Shape Anisotropy
FeSi flakes with high diameter possess higher permittivity for the larger specific areas and higher permeability for the increased shape anisotropy. [1] For the Co nanowires with the same morphology and diameter, the coercivity increases substantially with increasing aspect ratio of the nanowires due to the increased shape anisotropy when the aspect ratio is less than 3. [2]具有大直径的 FeSi 薄片对于较大的比面积具有较高的介电常数，对于增加的形状各向异性具有较高的磁导率。 [1] nan [2]
Cell Shape Anisotropy
The joint effect of boundary conditions, cell shape anisotropy, swimming speed, and flow speed leads to the nonmonotonic variations of the phenomenological dispersion coefficients. [1] Depending on the level of cell shape anisotropy or the strength of the polarity domain, one dominates the other and determines the orientation of the spindle. [2]边界条件、细胞形状各向异性、游泳速度和流速的共同作用导致了唯象色散系数的非单调变化。 [1] 根据细胞形状各向异性的水平或极性域的强度，一个支配另一个并决定了纺锤体的方向。 [2]
Plane Shape Anisotropy
We reported microwave measurements on a nanoscale MgO-based magnetic tunnel junction having an elliptical shape with large aspect ratios to obtain enough in-plane shape anisotropy to ensure free layer magnetization along the long axis. [1] To investigate the feasibility of the writing scheme, bilayered nano-pillars composed of a soft layer with small in-plane shape anisotropy and a hard layer with either large perpendicular anisotropy (PMA) or in-plane anisotropy (IMA) are designed and their switching behaviors are studied. [2]我们报道了对纳米级 MgO 基磁性隧道结的微波测量，该磁性隧道结具有大纵横比的椭圆形状，以获得足够的面内形状各向异性，以确保沿长轴的自由层磁化。 [1] 为了研究书写方案的可行性，设计了由具有小的面内形状各向异性的软层和具有大的垂直各向异性（PMA）或面内各向异性（IMA）的硬层组成的双层纳米柱，并对其进行切换行为被研究。 [2]
shape anisotropy contribution
In our micromagnetic simulations we considered yttrium iron garnet (YIG) as the FM layer and platinum the NM for the spin-pumped current calculations, and the stress contribution was introduced as an additional term in the effective anisotropy constant which also comprised the magnetocrystalline and shape anisotropy contributions of YIG. [1] The measurements obtained from the assembly of the obtained nanodots were analyzed by means of shape anisotropy contribution. [2]在我们的微磁模拟中，我们将钇铁石榴石 (YIG) 作为 FM 层，将铂作为 NM 用于自旋泵浦电流计算，并且引入应力贡献作为有效各向异性常数的附加项，该常数还包括磁晶和形状YIG 的各向异性贡献。 [1] nan [2]
shape anisotropy energy
By varying the thickness of the nanomagnets with different aspect ratio, the self-biased operation is obtained for a particular range where the lower limit is imposed by the thermal stability and the upper limit is given by the shape anisotropy energy. [1] Nanomagnets with small shape anisotropy energy barriers on the order of the thermal energy have unstable magnetization that fluctuates randomly in time. [2]通过改变具有不同纵横比的纳米磁体的厚度，在特定范围内获得自偏操作，其中下限由热稳定性施加，上限由形状各向异性能量给出。 [1] nan [2]
shape anisotropy originating
In contrast to pseudo periodic boundary conditions, which are widely used in micromagnetic codes, the presented methods eliminate the shape anisotropy originating from the outer boundary. [1] The improvement is due to phase purity, stable single-domain (SSD) size, and shape anisotropy originating from the prolate spheroid particles. [2]与在微磁代码中广泛使用的伪周期性边界条件相比，所提出的方法消除了源自外边界的形状各向异性。 [1] 这种改进是由于相纯度、稳定的单畴 (SSD) 尺寸和源自长球状颗粒的形状各向异性。 [2]