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Related papers: Superconductivity in Hydrogenated Graphites

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Unique to certain unconventional superconductors is the coexistence of magnetism and superconductivity. We have previously found ferromagnetism and superconductivity in hydrogenated graphitic materials. Herein we present similar as well as…

Superconductivity · Physics 2022-06-20 Nadina Gheorghiu , Charles R. Ebbing , Timothy J. Haugan

Experimental evidence of novel phenomena in hydrogenated graphite fibers is found. An indirect excitonic mechanism is likely leading to a SC state below the temperature Tc = 50 K, where the gap is divergent. Analysis of the gap within the…

Superconductivity · Physics 2023-02-15 Nadina Gheorghiu , Charles R. Ebbing , Timothy J. Haugan

It has been reported that graphite hosts room temperature superconductivity. Here we provide new results that confirm these claims on different samples of highly oriented pyrolytic graphite (HOPG) and commercial flexible graphite gaskets…

In this work, we have studied the effects from increasing the strength of the applied electric field on the charge transport of hydrogenated graphitic fibers. Resistivity measurements were carried out for direct currents in the nA - mA…

Materials Science · Physics 2020-05-19 Nadina Gheorghiu , Charles R. Ebbing , Timothy J. Haugan

In our previously published work, we have reported colossal magnetoresistance, Andreev oscillations, ferromagnetism, and granular superconductivity in oxygen-implanted carbon fibers, graphite foils, and highly oriented pyrolytic graphite.…

In this letter we describe the observation of a magnetic field dependent electronic gap, suggestive of local superconductivity, in the point-contact spectrum of micro-crystalline graphite. Magnetic field dependent point-contact spectroscopy…

Superconductivity · Physics 2018-05-23 Frank Arnold , Jan Nyeki , John Saunders

Superconductivity with transition temperature $T_c=1.7$ K has been reported in bilayer graphene [1,2]. The main factors, which may shed light on the mechanism of the formation of this superconductivity, are the following. Superconductivity…

Superconductivity · Physics 2018-06-22 G. E. Volovik

Within the BCS theory of superconductivity we calculate the superconducting gap at zero temperature for metallic hydrogen-graphene system in order to estimate the superconducting critical temperature of quasi two dimensional highly oriented…

Superconductivity · Physics 2009-02-11 N. García , P. Esquinazi

The temperature dependence of electric transport properties of single-layer and few-layer graphene at large charge doping is of great interest both for the study of the scattering processes dominating the conductivity at different…

Mesoscale and Nanoscale Physics · Physics 2016-09-02 R. S. Gonnelli , F. Paolucci , E. Piatti , Kanudha Sharda , A. Sola , M. Tortello , Jijeesh R. Nair , C. Gerbaldi , M. Bruna , S. Borini

The electronic and transport properties of graphene modulated by magnetic barrier arrays are derived for finite temperature. Prominent conductance gaps, originating from quantum interference effects are found in the periodic array case.…

Mesoscale and Nanoscale Physics · Physics 2015-04-30 Nojoon Myoung , Elefterios Lidorikis

We review experimental results, from transport to magnetization measurements, on different graphite samples, from bulk oriented graphite, thin graphite films to transmission electron microscope lamellae, that indicate the existence of…

Superconductivity · Physics 2013-12-17 Pablo Esquinazi

High resolution magnetoresistance data in highly oriented pyrolytic graphite thin samples manifest non-homogenous superconductivity with critical temperature $T_c \sim 25 $K. These data exhibit: i) hysteretic loops of resistance versus…

A magnetic-field-driven transition from metallic- to semiconducting-type behavior in the basal-plane resistance takes place in highly oriented pyrolytic graphite at a field $H_c \sim 1~$kOe applied along the hexagonal c-axis. The analysis…

Strongly Correlated Electrons · Physics 2009-10-31 H. Kempa , Y. Kopelevich , F. Mrowka , A. Setzer , J. H. S. Torres , R. Höhne , P. Esquinazi

We have observed periodically repeated steps in the resistance vs. temperature characteristics of doped Highly Oriented Pyrolytic Graphite and exfoliated doped multi-layer graphene. The observations consist of a series of regularly spaced…

Superconductivity · Physics 2013-07-03 Grover Larkins , Yuriy Vlasov , Kiar Holland

Pd-metal graphite (Pd-MG) has a layered structure, where each Pd sheet is sandwiched between adjacent graphene sheets. DC magnetization and AC magnetic susceptibility of Pd-MG have been measured using a SQUID magnetometer. Pd-MG undergoes a…

Superconductivity · Physics 2016-08-16 Masatsugu Suzuki , Itsuko S. Suzuki , Jürgen Walter

The carrier density in tens of nanometers thick graphite samples (multi-layer-graphene, MLG) has been modified by applying a gate voltage ($V_g$) perpendicular to the graphene planes. Surface potential microscopy shows inhomogeneities in…

Superconductivity · Physics 2014-02-04 A. Ballestar , P. Esquinazi , J. Barzola-Quiquia , S. Dusari , F. Bern , R. R. da Silva , Y. Kopelevich

We have identified ferromagnetic- and superconducting-like magnetization hysteresis loops in highly oriented pyrolytic graphite samples below and above room temperature. We also found that both behaviors are very sensitive to…

Strongly Correlated Electrons · Physics 2007-05-23 Y. Kopelevich , P. Esquinazi , J. H. S. Torres , S. Moehlecke

We report magnetization measurements performed on graphite--sulfur composites which demonstrate a clear superconducting behavior below the critical temperature T$_{c0}$ = 35 K. The Meissner-Ochsenfeld effect, screening supercurrents, and…

Superconductivity · Physics 2009-11-07 R. Ricardo da Silva , J. H. S. Torres , Y. Kopelevich

Sulfur intercalated graphite composites with diamagnetic transitions at 6.7 K and 37 K are prepared. The magnetization hysteresis loops (MHL), Xray diffraction patterns, and resistance were measured. From the MHL, a slight superconducting…

Superconductivity · Physics 2009-11-07 H. P. Yang , H. H. Wen , Z. W. Zhao , S. L. Li

Superconducting characteristics such as the Meissner-Ochsenfeld state, screening supercurrents and hysteresis loops of type-II superconductors were observed from the temperature and magnetic field dependences of the magnetic moment, m(T,…

Superconductivity · Physics 2009-11-07 S. Moehlecke , Pei-Chun Ho , M. B. Maple
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