论文标题
分级和步骤中的亚竞争性，例如蓝贝克铁磁铁的田间变化和各向异性的变化
Metastability in graded and step like variation of field and anisotropy of the Blume-Capel ferromagnet
论文作者
论文摘要
在分级和逐步的磁场变化的影响下，通过使用Metropolis单个Spin Flip Flip Algorithm进行了广泛的Monte Carlo模拟研究，已经研究了二维各向异性的Blume-Capel Ferromagnet的亚稳态行为。从最初的完美有序状态开始，在田间存在下已经研究了磁化的逆转。已经研究了具有均匀各向异性的系统以及在存在分级和阶梯式场的情况下的磁性持续寿命或磁性的逆转时间。在存在统一场的情况下，对{\它进行了分级和踩踏的各向异性系统}也探索了相同的探索。提出了有限尺寸效应的逆转时间变化（$ g_h $）和缩放关系$ \ langleτ\ rangle \ sim l^{ - β} f（g_h l^α）$。在磁化逆转时，还研究了投影状态的密度谱的空间变化（即+1、0和-1）。研究了每个位点旋转数量的空间变化。研究了界面（或域壁）具有田间梯度和各向异性梯度的运动，并发现在这两种情况下都遵循双曲线切线的行为。由于各向异性和应用领域都对亚稳态的寿命都有重大影响，因此在分级场中的{\ ralt级各向异性系统}和{\ a {\ sTepped Field}阶梯式各向异性系统}观察到了有趣的竞争情况}。在两种情况下，都发现了一系列边缘竞争，这两种情况将占主导地位的逆转和各向异性区域占主导地位。发现亚稳号的衰减遵循Avrami定律。观察到平均逆转时间在跨铁para跃迁的整个相边界上单调降低。
The metastable behaviour of two dimensional anisotropic Blume-Capel ferromagnet, under the influence of graded and stepped like variations of magnetic field, has been investigated by extensive Monte Carlo simulation using Metropolis single spin flip algorithm. Starting from the initial perfectly ordered state, reversal of magnetisation has been studied in presence of the field. Metastable lifetime or the reversal time of magnetisation for the system having uniform anisotropy and in the presence of both graded and stepped field has been studied. Also the same has been explored for a {\it graded and stepped anisotropic system} in presence of a uniform field. Finite size effect is analyzed for the variation of reversal time with gradient of field ($G_h$) and a scaling relation $\langle τ\rangle \sim L^{-β} f(G_h L^α)$ is proposed. Spatial variation of density profile for the projection states (i.e., +1, 0 and -1) has also been studied at the moment of reversal of magnetisation. The spatial variation of the number of spin flips per site is studied. Motion of the interface (or domain wall) with the gradient of field and gradient of anisotropy are investigated and are found to follow the hyperbolic tangent like behaviours in both cases. Since, both the anisotropy and the applied field have significant impact on the metastable lifetime, an interesting competitive scenario is observed for a {\it graded anisotropic system in graded field} and a {\it stepped anisotropic system in stepped field}. A line of marginal competition has been found out for both the cases separating the regions of field dominated reversal and anisotropy dominated reversal. The decay of the metastable volume fraction was found to follow the Avrami's law. The mean reversal time was observed to decrease monotonically across the phase boundary of the ferro-para transition.
