Related papers: Superconducting Behavior of Interfaces in Graphite…
We have studied the magnetic response of two bulk highly oriented pyrolytic graphite (HOPG) samples with different internal microstructure. For the sample with well defined interfaces, parallel to the graphene layers, the temperature and…
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…
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…
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…
In the last 43 years several hints were reported suggesting the existence of granular superconductivity above room temperature in different graphite-based systems. In this paper some of the results are reviewed, giving special attention to…
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…
At low temperatures, graphite presents a magnetoresistance anomaly which manifests as a transition to a high-resistance state (HRS) above a certain critical magnetic field $\text{B}_\text{c}$. Such HRS is currently attributed to a c-axis…
In this work we investigated correlations between the internal microstructure and sample size (lateral as well as thickness) of mesoscopic, tens of nanometer thick graphite (multigraphene) samples and the temperature $(T)$ and field $(B)$…
We have measured the magnetic field and temperature dependence of the resistivity of several micrometers long and heterogeneously thick graphite sample. The magnetoresistance results for fields applied nearly parallel to the graphene planes…
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…
The hysteresis of magnetoresistance observed in superconductors is of great interest due to its potential connection with unconventional superconductivity. In this study, we perform electrical transport measurements on Kagome superconductor…
We report the observation of proximity effect in measurements performed on highly oriented pyrolitic graphite (HOPG) samples when electrical current is injected through the superconducting electrodes placed on the sample surface few…
In spite of 40 years of experimental studies and several theoretical proposals, an overall interpretation of the complex behavior of the magnetoresistance (MR) of multilayer graphene, i.e. graphite, at high fields ($B \lesssim 70~$T) and in…
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…
We have studied the transport properties of transmission electron microscope (TEM) lamellae obtained from a pyrolytic graphite sample of grade B (SPI-II) with electrical contacts at the edges of the graphene layers. The temperature,…
We argue that the superconducting state found in high-$T_c$ cuprates is inhomogeneous with a corresponding inhomogeneous superfluid density. We introduce two classes of microscopic models which capture the magnetic and superconducting…
The ordinary magnetoresistance (MR) of doped semiconductors is positive and quadratic in a low magnetic field, B, as it should be in the framework of the Boltzmann kinetic theory or in the conventional hopping regime. We observe an unusual…
We report transport and magnetization measurements on graphitic materials that have been hydrogenated after being treated with octane. The temperature-dependent electrical resistivity shows anomalies manifested as re-entrant insulator-metal…
We investigated the influence of thickness reduction on the transport properties of graphite microflakes. Using oxygen plasma etching we decreased the thickness of highly oriented pyrolytic graphite (HOPG) microflakes from $\sim 100$~nm to…
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…