Superconducting Fullerene Nanowhiskers

Abstract

Abstract:We synthesized superconducting fullerene nanowhiskers (C 60 NWs) by potassium (K) intercalation. They showed large superconducting volume fractions, as high as 80%. The superconducting transition temperature at 17 K was independent of the K content (x) in the range between 1.6 and 6.0 in K-doped C 60 nanowhiskers (K x C 60 NWs), while the superconducting volume fractions changed with x. The highest shielding fraction of a full shielding volume was observed in the material of K 3.3 C 60 NW by heating at 200 °C. On the other hand, that of a K-doped fullerene (K-C 60 ) crystal was less than 1%. We report the superconducting behaviors of our newly synthesized K x C 60 NWs in comparison to those of K x C 60 crystals, which show superconductivity at 19 K in K 3 C 60 . The lattice structures are also discussed, based on the x-ray diffraction (XRD) analyses.

Precise Raman measurements of C₆₀ fullerene nanowhiskers synthesized using the liquid-liquid interfacial precipitation method

“…Each band's uncertainty is given by uref(xi) = (standard deviation of Raman shift for the i-th band of the reference samples) / (8) where l is the number of laboratories participating in the measurement of the reference samples Raman shifts given in the ASTM standard. ufit = the mean value of all (ufit for a measurement), (9) ufit for a measurement = standard error of Ag(2) peak in a fitted curve. (10) For this study, a = -1.1343 cm-1, b = 0.99816, l = 7 [33], m = 100, and n = 104. xi and yi are the values of coordinates in Fig.…”

“…The extent of polymerization can be known using the down shift value of Ag(2) peak from the intrinsic 1469 cm -1 of pristine C60 solid [1]. On the other hand, C60 fullerene nanowhiskers (C60FNWs) are thin needle-like crystals composed of C60 molecules with diameter less than 1000 nm, and they have many applications, such as field-effect transistors, solar cells, photocatalysts, photosensors, scaffolds for cell growth, superconductors and templates for chemical synthesis [7][8][9][10][11][12].…”

Multiconfigurational Study of the Electronic Structure of Negatively Charged Fullerens

“…In addition to interesting physical and chemical properties of fullerenes, such as: superconductivity [1,2], nonlinear optics [3], ferromagnetism [4,5] and applications in solar cells [6,7], is an interesting object to study localized electronic states, magnetic properties and metal to insulator transitions [8,9]. In ordinary solids, it is difficult to observe localized charged states on a long distance, but individual fullerenes are spatially isolated, thus a pair of molecules can be used to model a system with two localized spins, similar to a diatomic molecule, but on significantly larger distance between centers.…”

Intercalation of Metallic Potassium and Fullerene C60 into Natural Graphite

“…Fullerene in the form of the so-called "nanowhiskers", prepared by the LLIP method (Liquid -Liquid Interfacial Precipitation Polymer), was intercalated to produce K 3,3 C 60 NWS with supraconductive properties (Takeya et al, 2012).…”