Percolative composites with negative permittivity have attracted much attention. For carbonyl iron and La-doped barium ferrite composites, the conduction mechanism changed from hopping conduction to metal-like conduction when carbonyl iron content increased. When carbonyl iron content was 80 wt%, which exceeded but approached the percolation threshold, a weak value of negative permittivity between −200 and 0 was achieved. In addition, the analysis of reactance revealed that inductance characteristic resulted in the negative permittivity. This work provides a way to design the metal composites with a weakly negative permittivity to apply in different fields.

具有负介电常数的渗透复合材料引起了广泛关注。对于羰基铁和La掺杂的钡铁氧体复合材料，当羰基铁含量增加时，其传导机制从跳跃传导转变为类金属传导。当羰基铁含量为 80 wt% 时，超过但接近渗透阈值时，实现了介于 -200 和 0 之间的弱负介电常数值。此外，电抗分析表明，电感特性导致了负介电常数。这项工作提供了一种设计具有弱负介电常数的金属复合材料以应用于不同领域的方法。