School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel.
School of Physical Science, National Institute of Science Education and Research, Bhubaneswar 752050, India.
Sensors (Basel). 2023 Feb 22;23(5):2409. doi: 10.3390/s23052409.
We discuss the effect of topological inhomogeneity of very thin metallic conductometric sensors on their response to external stimuli, such as pressure, intercalation, or gas absorption, that modify the material's bulk conductivity. The classical percolation model was extended to the case in which several independent scattering mechanisms contribute to resistivity. The magnitude of each scattering term was predicted to grow with the total resistivity and diverge at the percolation threshold. We tested the model experimentally using thin films of hydrogenated palladium and CoPd alloys where absorbed hydrogen atoms occupying the interstitial lattice sites enhance the electron scattering. The hydrogen scattering resistivity was found to grow linearly with the total resistivity in the fractal topology range in agreement with the model. Enhancement of the absolute magnitude of the resistivity response in the fractal range thin film sensors can be particularly useful when the respective bulk material response is too small for reliable detection.
我们讨论了非常薄的金属导电传感器的拓扑非均匀性对其对外界刺激（如压力、嵌入或气体吸收）响应的影响，这些刺激会改变材料的体电导率。经典的渗流模型被扩展到了几种独立的散射机制对电阻率有贡献的情况。预测每个散射项的大小随总电阻率的增加而增加，并在渗流阈值处发散。我们使用氢化钯和 CoPd 合金的薄膜进行了实验验证，其中占据间隙晶格位置的吸附氢原子增强了电子散射。在分形拓扑范围内，发现氢散射电阻率随总电阻率线性增长，与模型一致。当各自的体材料响应太小而无法可靠检测时，分形范围薄膜传感器中电阻率响应的绝对值增强可能特别有用。
