Two-dimensional percolation phase transition in ultrathin Co/Cu(110)
Two-dimensional percolation phase transition in ultrathin Co/Cu(110)
复制标题
超薄Co/Cu(110)中的二维渗流相变
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
J. Bland
中科院分区：
文献类型：
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作者：
S. Hope;M. Tselepi;E. Gu;T. M. Parker;J. Bland
在铁磁有序开始的临界区附近，磁化率χ服从幂律，临界指数γ=2.39±0.08，与理想二维几何渗流相变的理论值非常吻合.扫描隧道显微镜的研究表明，通过形成三维细长的岛状结构，形成一个阵列的Co“纳米磁体”的Co生长。这种有序转变是Co岛之间直接交换发展的结果。铁磁相的面内单轴各向异性主要归因于Co岛的内部偶极场。
Near the critical region for the onset of ferromagnetic order, the magnetic susceptibility χ follows a power law with a critical exponent γ=2.39±0.08, in excellent agreement with the theoretical value for a perfect two-dimensional geometric percolation phase transition. Scanning tunneling microscopy studies reveal that the Co grows via the formation of three-dimensional elongated island structures, forming an array of Co “nanomagnets.” The ordering transition is a consequence of direct exchange developing between Co islands. The in-plane uniaxial anisotropy in the ferromagnetic phase is predominantly attributed to the internal dipolar field of the Co islands.