Using dc transport and wide-band spectroscopic ellipsometry techniques, we study localization effects in the disordered metallic Ta interlayer of different thicknesses in the multilayer films (MLFs) (Ta–FeNi)N grown by rf sputtering deposition. In the grown MLFs, the FeNi layer was 0.52 nm thick, while the Ta layer thickness varied between 1.2 and 4.6 nm. The Ta layer dielectric function was extracted from the Drude-Lorentz simulation. The dc transport study of the MLFs implies non-metallic (dρ/dT<0) behavior, with negative temperature coefficient of resistivity (TCR). The TCR absolute value increases upon increasing the Ta interlayer thickness, indicating enhanced electron localization. With that, the free charge carrier Drude response decreases. Moreover, the pronounced changes occur in the extended spectral range, involving the higher-energy Lorentz bands. The Drude dc conductivity drops below the weak localization limit for the thick Ta layer. The global band structure reconstruction may indicate the ...

中文翻译：

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多层 Ta-FeNi 薄膜无序 Ta 夹层中的定位效应：来自直流输运和光谱椭偏研究的证据

使用直流输运和宽带光谱椭偏技术，我们研究了通过射频溅射沉积生长的多层膜 (MLF) (Ta-FeNi)N 中不同厚度的无序金属 Ta 夹层中的定位效应。在生长的 MLF 中，FeNi 层厚度为 0.52 nm，而 Ta 层厚度在 1.2 到 4.6 nm 之间变化。Ta 层介电函数是从 Drude-Lorentz 模拟中提取的。MLF 的直流输运研究意味着非金属 (dρ/dT<0) 行为，具有负的电阻温度系数 (TCR)。TCR 绝对值随着 Ta 夹层厚度的增加而增加，表明电子局域化增强。因此，自由电荷载体德鲁德响应降低。此外，显着的变化发生在扩展的光谱范围内，涉及更高能量的洛伦兹带。Drude dc 电导率低于厚 Ta 层的弱局部化极限。全局能带结构重建可能表明...