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At a very low critical temperature KC8 presents superconducting properties

Thanks to the unique electronic structure, KC₈ (19-1935) serves as an excellent reducing agent for various chemical transformations and as an essential component of next-generation potassium-ion batteries. Furthermore, K ion-based graphite intercalate compounds (K-GICs) have been well-known for a long time to have superconducting properties [1]. At a very low critical temperature Tc = 0.14 K, KC₈ becomes a superconductor.

There has been a considerable debate about the mechanism and the electrons responsible for the superconductivity. The question has centered on whether the electrons responsible for the superconductivity reside in the graphite π*-bands, the intercalant bands or a combination of both. The relevant experimental results that must be explained are the trend in T_c between the different GICs and the anisotropy of the superconducting upper critical field [2-3].

Since the first discovery of the KC₈ superconductor, many other GICs have been found to be superconducting. Among the superconducting GICs, CaC₆ exhibits the highest critical temperature T_c = 11.5 K [4]. More recently, Cao et al reported the successful synthesis of superconducting potassium-doped few-layer graphene (K-doped FLG) with a transition temperature of 4.5 K, which is one order of magnitude higher than that observed in the bulk KC₈ (T_c = 0.39 K) [5]. First stage K-GICs is also used as a reference material for the superconducting organic materials. Gao et al studied the atomic structures and electronic properties of potassium-doped phenanthrene with various doping levels [6].

References:

1.       Phys. Rev. Lett. 1965, 14, 225.
2.       Phys. Rev. B, 2009, 79, 205106.
3.       Phys. Rev. Lett. 2011, 106, 187002.
4.       Sci. Technol. Adv. Mater. 2008, 9, 044102.
5.       J. Am. Chem. Soc. 2012, 134, 6536.
6.       J. Mater. Chem. C, 2016, 4, 11566.

Featured Product:

19-1935 Potassium graphite KC8 (12081-88-8)

Related Blogs:

Potassium Graphite KC8 – An Excellent Reducing Agent
Potassium Graphite Electrodes for Potassium Ion Batteries

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High Purity Chemicals for Materials R&D