Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, 50009-Zaragoza, Spain. Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009-Zaragoza, Spain.
J Phys Condens Matter. 2010 Feb 10;22(5):056003. doi: 10.1088/0953-8984/22/5/056003. Epub 2010 Jan 15.
The evolution of the morphology, magnetic and transport properties of Fe(t nm)/MgO(3.0 nm) multilayers with respect to the nominal metallic layer thickness was investigated. A comparison with existing experimental data on discontinuous metal-insulator multilayers, ultrathin epitaxial Fe films on MgO substrates and granular cermet films is made. It is confirmed that the deposition conditions and the material composition play a crucial role in the percolation process. Nominal thicknesses of Fe layers at which an infinite metallic cluster is formed and the conditions for continuous Fe coverage were determined. Different methods of percolation threshold detection were analysed. We show that investigation of the temperature dependence of resistance in nanostructures could lead to an overestimation of the percolation threshold value, while magnetic measurements alone could lead to its underestimation.
研究了 Fe(t nm)/MgO(3.0 nm) 多层膜的形态、磁性和输运性质随名义金属层厚度的变化。与不连续金属-绝缘体多层膜、MgO 衬底上外延的超薄 Fe 膜和颗粒金属陶瓷膜的现有实验数据进行了比较。证实了沉积条件和材料组成在渗流过程中起着至关重要的作用。确定了形成无限金属簇的名义 Fe 层厚度和连续 Fe 覆盖的条件。分析了不同的渗流阈值检测方法。我们表明，研究纳米结构中电阻的温度依赖性可能导致对渗流阈值值的高估，而仅进行磁测量可能导致对其的低估。
