Publisher's Note: Observation of an ultrahigh-temperature ferromagnetic-like transition in iron-contaminated multiwalled carbon nanotube mats [Phys. Rev. B77, 245433 (2008)]

Quantum statistical model for superconducting phase in graphene and nanotubes

“…Zhao and his group [1] found an experimental evidence of superconductivity in multi-walled nanotubes (MWNT) with the critical temperature T c = 1275 K after examining the paramagnetic Meissner effect [2]. This is a new record of high T c , about eight times higher than T c = 164 K found in mercury-based cuprates [3].…”

“…( 3), we obtain the critical temperature T c = 1275 K, for n 0 = 7.33×10 11 cm −2 . The measurments of the satulation magnetization of MWNT bundle [1] yield the 3D electron density 2.12×10 19 cm −3 , which give a 2D density (2.12) 2/3 × 10 12 cm −2 . The pairon density must be smaller than the electron density.…”

Three small systems showing probable room-temperature superconductivity

“…After first suggestions of possible room-temperature superconductivity in multiwalled carbon nanotubes by Tsebro and coworkers [6], Zhao and coworkers gave evidence from 2001 [7,8,9] from their own results and published data of others that superconductivity occurs for temperatures up to over 700 K in multiwalled nanotubes or mats of single-walled or multiwalled nanotubes. The evidence is from resistance analysed by a slightly modified version of the Langer-Ambegoakar-McCumber-Halperin (LAMH) theory of resistance due to phase slips, from diamagnetic susceptibility much reduced from a full Meissner effect due to magnetic field penetration depths being larger in magnitude than tube diameters, tunnelling results showing large energy gaps, and analysis of the temperature dependence of Raman data for phonons of energy close to the energy gap.…”

Modification of a Charged-Bose-Gas Model for Observed Room-Temperature Superconductivity in Narrow Channels Through Films of Oxidized Atactic Polypropylene

“…However, an early paper from the Ioffe Institute, and also more recent work by some scientists from the Ioffe Institute, especially Ionov, who was a member of the original group publishing in 1990, collaborating with others from Russia and Germany, have found evidence that superconductivity occurs in narrow channels through many polymer films at temperatures below the T c of superconducting electrodes, and that this is not due to the superconducting proximity effect. Such evidence includes conductivity greater than 10 14 Ω −1 cm −1 in channels through films between superconducting Sn electrodes [4], Josephson-like I-V curves for superconductor-polymersuperconductor sandwiches in OAPP [4], PDMS [24], poly(phthalidylidene biphenyline) [34], polyamidine [25], and two other polymers [35], oscillations of resistance as a function of magnetic field in films of polyimide, poly(phthalidylidene biphenylene) and PDMS below the T c of Sn [36,24,34], and a critical current for a destruction of Josephson-like I − V curves which depends on temperature in a way inconsistent with superconductivity due to the proximity effect in PDMS [24] and poly(phthalidylidene biphenylene) [34,37]. There is also a large number of papers by the group of A.N.…”

“…[6], and depended on the lack of decomposition of the sample after repeated pulsed measurements, which permitted a deduction of conductivity greater than 10 11 ohm −1 cm −1 , and a transition temperature from the highly conducting state under pulsed-current conditions of at least 700 K, the decomposition temperature of the polymer. Similar very high superconducting T c 's have been inferred by Zhao and coworkers [7,8,9,10] from conductivity and other measurements on carbon nanotubes, following a suggestion by Tsebro et al [11] that there might be superconductivity at room temperature in carbon nanotubes. Work claiming possible room-temperature superconductivity in highly oriented pyrolytic graphite [12,13] may be related.…”