AC conductivity and correlation effects in nano-granular Pt/C.
AC conductivity and correlation effects in nano-granular Pt/C.
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DOI：
10.1038/s41598-021-94575-w
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发表时间：
2021-07-26
影响因子：
4.6
通讯作者：
Huth M
中科院分区：
文献类型：
--
作者：
Hanefeld M;Gruszka P;Huth M
纳米颗粒金属是属于颗粒电子系统的一般类别的材料，其中可以研究电子相关性，无序和有限尺寸效应的相互作用。纳米颗粒金属中的电荷输运主要是由热辅助的、顺序的和相关的隧穿过程控制的。在这里，我们研究的频率依赖的电导率（交流电导率）的纳米颗粒铂与Pt纳米颗粒嵌入到无定形碳（C）。我们专注于运输制度的绝缘体金属过渡的绝缘侧上所反映的一组样品覆盖的隧道耦合强度的范围。在这种运输制度的极化贡献的AC电导率是小的和相关的自由电荷的运输效果预计将特别明显。我们发现一个普遍的行为，可以追溯到温度依赖的零频率电导率（直流电导率）的Pt/C在一个简单的集总电路分析的频率依赖性。我们的研究结果是在对比以前的工作纳米颗粒Pd/在非常弱的耦合制度，极化贡献的AC电导率占主导地位。我们描述了纳米颗粒金属在介电材料的近接阻抗谱中可能的未来应用。
Nano-granular metals are materials that fall into the general class of granular electronic systems in which the interplay of electronic correlations, disorder and finite size effects can be studied. The charge transport in nano-granular metals is dominated by thermally-assisted, sequential and correlated tunneling over a temperature-dependent number of metallic grains. Here we study the frequency-dependent conductivity (AC conductivity) of nano-granular Platinum with Pt nano-grains embedded into amorphous carbon (C). We focus on the transport regime on the insulating side of the insulator metal transition reflected by a set of samples covering a range of tunnel-coupling strengths. In this transport regime polarization contributions to the AC conductivity are small and correlation effects in the transport of free charges are expected to be particularly pronounced. We find a universal behavior in the frequency dependence that can be traced back to the temperature-dependent zero-frequency conductivity (DC conductivity) of Pt/C within a simple lumped-circuit analysis. Our results are in contradistinction to previous work on nano-granular Pd/ in the very weak coupling regime where polarization contributions to the AC conductivity dominated. We describe possible future applications of nano-granular metals in proximity impedance spectroscopy of dielectric materials.
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DOI：
10.1007/s00339-014-8631-9
发表时间：
2014-12-01
影响因子：
2.7
作者：
Huth, Michael;Kolb, Florian;Plank, Harald
通讯作者：
Plank, Harald
影响因子：
1.6
作者：
Huth, Michael;Gruszka, Peter;Keller, Lukas
通讯作者：
Keller, Lukas
影响因子：
3.5
作者：
NAMIKAWA, H
通讯作者：
NAMIKAWA, H
影响因子：
1.4
作者：
Plank, Harald;Kothleitner, Gerald;Krenn, Joachim R.
通讯作者：
Krenn, Joachim R.
影响因子：
4.6
作者：
Bakkali H;Dominguez M;Batlle X;Labarta A
通讯作者：
Labarta A