相关论文: Observation of double percolation transitions in A…

A double percolation transition is identified in a binary network composed of nanoparticles of magnesium diborade superconductor and chromium oxide half-metallic ferromagnet. Anomalously high-resistance or insulating state, as compared to…

We have studied the low-temperature electrical transport properties of Pb$_x$(SiO$_2$)$_{1-x}$ ($x$ being the Pb volume fraction) nanogranular films with thicknesses of $\sim$1000 nm and $x$ spanning the dielectric, transitional, and…

We investigate transport and magnetotransport properties of binary networks composed of superconducting (MgB2) and ferromagnetic (CrO2 or LSMO) nanoparticles. While for the LSMO/MgB2 system a single percolation threshold is observed, for…

We demonstrate switching behavior and quantized conductance at room temperature in percolating films of nanoparticles. Our experiments and complementary simulations show that switching and quantization result from formation of atomic scale…

We have studied the temperature dependence of conductivity, $\sigma(T)$, in two series of Ag$_{x}$(SnO$_2$)$_{1-x}$ and Mo$_{x}$(SnO$_2$)$_{1-x}$ granular films lying below the percolation threshold, where $x$ is the metal volume fraction.…

Percolation phenomena are investigated and discussed in three kinds of nanostructures: first two are nanocrystalline silicon-based systems, Si nanodots embedded in amorphous SiO2 matrix and porous silicon formed by an oxidized nanowire…

The microstructure and electrical transport of Cr$_x$(SiO$_2$)$_{1-x}$ nanogranular films with Cr volume faction $x$$\simeq$0.67 and 0.72 are systematically investigated. The transmission electron microscopy images and elemental mappings…

Recent observations of superconducting like transition at 286 K in Ag and Ag nanostructures by Thapa et al. (arxiv: 1807.08572) have rekindled the hope for room temperature superconductivity under ambient conditions. We also investigated…

Theory of quantum corrections to conductivity of granular metal films is developed for the realistic case of large randomly distributed tunnel conductances. Quantum fluctuations of intergrain voltages (at energies E much below bare charging…

Films of metal-insulator nanogranular composites M$_x$D$_{100-x}$ with different compositions and atomic percentage of metal and dielectric phases (M = Fe, Co, Ni, CoFeB; D = Al$_2$O$_3$, SiO$_2$, ZrO$_2$; x $\approx$ 15-60 at.%) are…

We have measured the differential conductances $G(V,T)$ in several Al/AlO$_{x}$/Sc planar tunnel junctions between 2 and 35 K. As the temperature decreases to $\sim$ 16 K, the zero-bias conductance $G(0,T)$ crosses over from a standard…

We report the demonstration of dc and ac Josephson effects as well as tunneling spectroscopy measurements on Nb/Al2O3/Al/MgB2 thin films heterostructures. Data on dc Josephson effect suggest the presence of two characteristic critical…

An oscillatory magnetic field dependence of the DC voltage is observed when a low-frequency current flows through superconducting Sn-Ge thin-film composites near the percolation threshold. The paper also studies the experimental…

We study the temperature dependence of the superconductor-insulator transition in granular superconductors. Empirically, these systems are characterized by very broad resistance tails, which depend exponentially on the temperature, and the…

Au and Ag are known to be metallic and none of them have shown independently superconductivity. Here we show superconductivity in Ag implanted Au thin films. Ag implanted Au films of different thicknesses have been studied using four probe…

The single electron tunneling spectroscopy on superconductor Na$_{x}$CoO$_2$$\cdot$ yH$_2$O and its starting compound Na$_{x}$CoO$_2$ has been studied with point-contact method. The spectra of Na$_{x}$CoO$_2$ have two types of distinct…

Superconductivity realized in bilayer nickelate thin films enables direct spectroscopic and transport studies at ambient pressure. However, a persistent two-step resistive transition remains a major barrier to achieving optimal…

Thin films consisting of Ag and Au nanoparticles embedded in amorphous ZrO2 matrix were grown by pulsed laser deposition in a wide range of metal volume concentrations in the dielectric regime (0.08<x(Ag)<0.28 and 0.08<x(Au)<0.52). High…

Superconductivity in granular films is controlled by the grain size and the inter-grain coupling. In a two-component granular system formed by a random mixture of a normal metal (N) and a superconductor (S), the superconducting nano-grains…

Nanogranular metal composites, consisting of immiscible metallic and insulating phases deposited on a substrate, are characterized by two distinct electronic transport regimes depending on the relative amount of the metallic phase. At…