Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
Nat Mater. 2010 Feb;9(2):125-8. doi: 10.1038/nmat2587. Epub 2009 Nov 22.
Liquid/solid interfaces are attracting growing interest not only for applications in catalytic activities and energy storage, but also for their new electronic functions in electric double-layer transistors (EDLTs) exemplified by high-performance organic electronics, field-induced electronic phase transitions, as well as superconductivity in SrTiO(3) (ref. 12). Broadening EDLTs to induce superconductivity within other materials is highly demanded for enriching the materials science of superconductors. However, it is severely hampered by inadequate choice of materials and processing techniques. Here we introduce an easy method using ionic liquids as gate dielectrics, mechanical micro-cleavage techniques for surface preparation, and report the observation of field-induced superconductivity showing a transition temperature T(c)=15.2 K on an atomically flat film of layered nitride compound, ZrNCl. The present result reveals that the EDLT is an extremely versatile tool to induce electronic phase transitions by electrostatic charge accumulation and provides new routes in the search for superconductors beyond those synthesized by traditional chemical methods.
液体/固体界面不仅在催化活性和能量存储等应用中引起了越来越多的关注，而且在电双层晶体管（EDLT）中也具有新的电子功能，例如高性能有机电子、场诱导电子相变以及 SrTiO(3)（ref. 12）中的超导性。拓宽 EDLT 以在其他材料中诱导超导性，对于丰富超导材料的科学非常有必要。然而，由于材料选择和处理技术的不足，这一需求受到了严重阻碍。在这里，我们介绍了一种使用离子液体作为栅介质、机械微裂技术进行表面制备的简便方法，并报告了在层状氮化物化合物 ZrNCl 的原子级平坦薄膜上观察到的场诱导超导性，其转变温度 T(c)=15.2 K。这一结果表明，EDLT 是通过静电电荷积累诱导电子相变的极其通用的工具，并为寻找超越传统化学方法合成的超导材料提供了新途径。
