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Synthesis of fullerene nanowhiskers using the liquid – liquid interfacial precipitation method and their mechanical, electrical and superconducting properties

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ABSTRACT

Fullerene nanowhiskers (FNWs) are thin crystalline fibers composed of fullerene molecules, including C60, C70, endohedral, or functionalized fullerenes. FNWs display n-type semiconducting behavior and are used in a diverse range of applications, including field-effect transistors, solar cells, chemical sensors, and photocatalysts. Alkali metal-doped C60 (fullerene) nanowhiskers (C60NWs) exhibit superconducting behavior. Potassium-doped C60NWs have realized the highest superconducting volume fraction of the alkali metal-doped C60 crystals and display a high critical current density (Jc) under a high magnetic field of 50 kOe. The growth control of FNWs is important for their success in practical applications. This paper reviews recent FNWs research focusing on their mechanical, electrical and superconducting properties and growth mechanisms in the liquid–liquid interfacial precipitation method.

No MeSH data available.


Shielding volume fractions in K-doped C60NWs and K-doped C60 crystal powder (reprinted from [87]).
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Figure 6: Shielding volume fractions in K-doped C60NWs and K-doped C60 crystal powder (reprinted from [87]).

Mentions: Of the three known phases of K-doped C60 (fcc (K3C60), body-centered tetragonal (bct) (K4C60), and body-centered cubic (bcc) (K6C60)), only the fcc phase exhibits superconductivity [84]. Although C60NWs that are grown in solution display a solvated hexagonal structure, they transform into an fcc structure upon drying and removal of the internal solvent molecules [85]. Hence, these fcc C60NWs should be superconducting if doped with alkali metals [15]. C60 nanotubes were doped with Li, Na, and K, and the crystal structures were examined using Raman spectroscopy [86]. Superconductive C60NWs were also successfully fabricated by doping with K [87, 88]. Although the Tc value (17 K) of the K-doped C60NWs with a nominal composition of K3.3C60 was lower than the reported value of 18 K [82], the superconducting, shielding volume fraction was as high as 80%, and the critical current density Jc was more than 3 × 105 A cm−2 under 50 kOe [87, 88], although the doping was performed at 200 °C for 24 h. The shielding volume fraction of the K-doped C60 crystal powder was less than 1% when doped using the same process (figure 6). The high shielding volume fraction in the K-doped C60NWs may allow for light, flexible, and recyclable superconducting carbon cables. Initially, the superconducting shielding volume fraction of K-doped C60 crystals was at most 35%, even after prolonged heat treatment (20 days) at temperatures up to 250 °C [89].


Synthesis of fullerene nanowhiskers using the liquid – liquid interfacial precipitation method and their mechanical, electrical and superconducting properties
Shielding volume fractions in K-doped C60NWs and K-doped C60 crystal powder (reprinted from [87]).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036494&req=5

Figure 6: Shielding volume fractions in K-doped C60NWs and K-doped C60 crystal powder (reprinted from [87]).
Mentions: Of the three known phases of K-doped C60 (fcc (K3C60), body-centered tetragonal (bct) (K4C60), and body-centered cubic (bcc) (K6C60)), only the fcc phase exhibits superconductivity [84]. Although C60NWs that are grown in solution display a solvated hexagonal structure, they transform into an fcc structure upon drying and removal of the internal solvent molecules [85]. Hence, these fcc C60NWs should be superconducting if doped with alkali metals [15]. C60 nanotubes were doped with Li, Na, and K, and the crystal structures were examined using Raman spectroscopy [86]. Superconductive C60NWs were also successfully fabricated by doping with K [87, 88]. Although the Tc value (17 K) of the K-doped C60NWs with a nominal composition of K3.3C60 was lower than the reported value of 18 K [82], the superconducting, shielding volume fraction was as high as 80%, and the critical current density Jc was more than 3 × 105 A cm−2 under 50 kOe [87, 88], although the doping was performed at 200 °C for 24 h. The shielding volume fraction of the K-doped C60 crystal powder was less than 1% when doped using the same process (figure 6). The high shielding volume fraction in the K-doped C60NWs may allow for light, flexible, and recyclable superconducting carbon cables. Initially, the superconducting shielding volume fraction of K-doped C60 crystals was at most 35%, even after prolonged heat treatment (20 days) at temperatures up to 250 °C [89].

View Article: PubMed Central - PubMed

ABSTRACT

Fullerene nanowhiskers (FNWs) are thin crystalline fibers composed of fullerene molecules, including C60, C70, endohedral, or functionalized fullerenes. FNWs display n-type semiconducting behavior and are used in a diverse range of applications, including field-effect transistors, solar cells, chemical sensors, and photocatalysts. Alkali metal-doped C60 (fullerene) nanowhiskers (C60NWs) exhibit superconducting behavior. Potassium-doped C60NWs have realized the highest superconducting volume fraction of the alkali metal-doped C60 crystals and display a high critical current density (Jc) under a high magnetic field of 50 kOe. The growth control of FNWs is important for their success in practical applications. This paper reviews recent FNWs research focusing on their mechanical, electrical and superconducting properties and growth mechanisms in the liquid–liquid interfacial precipitation method.

No MeSH data available.