Related papers: Normal state properties of high angle grain bounda…
Temperature and magnetic field dependences of the conductivity of YBaCuO films in the transition region are analyzed taking into account spatial inhomogeneity in transition temperature, Tc. (i) An expression for the superconducting…
We describe a simple AC susceptometer built in-house that can be used to make high-resolution measurements of the magnetic susceptibility of high-temperature superconductors in an undergraduate physics lab. Our system, cooled using liquid…
The normal state and superconducting properties are investigated in the phase diagram of K_xSr_{1-x}Fe_2As_2 for 0<x<1. The ground state upper critical field, H_{c2}(0), is extrapolated from magnetic field dependent resistivity…
We report precise measurements to obtain the normal-state resistivity and the depairing current density of BaFe$_2$(As$_{1-x}$P$_x$)$_2$($x\sim0.29-0.32$) nanobridges along the $c$ axis, which are fabricated from single crystals near the…
High energy x-ray diffraction microscopy was used to image the microstructure of $\alpha$-Fe before and after a 600 $^\circ$C anneal. These data were used to determine the areas, curvatures, energies, and velocities of approximately 40,000…
The temperature dependence of the tunneling conductance was measured for various doping levels of Pr(2-x)CexCuO4 using planar junctions. A normal state gap is seen at all doping levels studied, x=0.11 to x=0.19. We find it to vanish above a…
Using molecular dynamics simulations and first principles calculations, we have studied the structure and mechanical strength of tilt grain boundaries in graphene sheets that arise during CVD growth of graphene on metal substrates.…
The residual low angle grain boundary (GB) network is still the most important current-limiting mechanism operating in bi-axially textured rare earth barium copper oxide (REBCO) coated conductors. While Ca-doping is well established to…
Grain boundaries (GBs) in metals usually increase electrical resistivity due to their distinct atomic arrangement compared to the grain interior. While the GB structure has a crucial influence on the electrical properties, its relationship…
The dependence of the critical current density Jc on hydrostatic pressure to 0.6 GPa is determined for a single 25-degree [001]-tilt grain boundary in a bicrystalline ring of nearly optimally doped melt-textured YBa2Cu3Ox. Jc is found to…
Normal state orbital diamagnetism of charged bosons quantitatively accounts for recent high-resolution magnetometery results near and above the resistive critical temperature Tc of superconducting cuprates. Our parameter-free descriptions…
We study the motion of a grain boundary separating two otherwise stationary domains of hexagonal symmetry. Starting from an order parameter equation appropriate for hexagonal patterns, a multiple scale analysis leads to an analytical…
We present the results of a computer simulation of the atomic structures of large-angle symmetrical tilt grain boundaries (GBs) $\Sigma 5$ (misorientation angles $\q{36.87}{^{\circ}}$ and $\q{53.13}{^{\circ}}$), $\Sigma 13$ (misorientation…
Grain boundaries are topological defects that often have a disordered character. Disorder implies that understanding general trends is more important than accurate investigations of individual grain boundaries. Here we present trends in the…
The discovery of superconductivity in copper oxide compounds has attracted considerable attention over the past three decades. The high transition temperature in these compounds, exhibiting proximity to an antiferromagnetic order in their…
We calculate the junction resistance for a metal-barrier-metal device with the barrier tuned to lie just on the insulating side of the metal-insulator transition. We find that the crossover from tunneling behavior in thin barriers at low…
The optical properties of single crystals of YBa_2Cu_3O_{6+x} have been examined along the c axis above and below the critical temperature (T_c) for a wide range of oxygen dopings. The temperature dependence of the optically-determined…
In light of the race towards macroscale superlubricity of graphitic contacts, the effect of grain boundaries on their frictional properties becomes of central importance. Here, we elucidate the unique frictional mechanisms characterizing…
Grain boundary structural transitions can lead to significant changes in the properties and performance of materials. In multi-principal element alloys, understanding these transitions becomes complex due to phenomena such as local chemical…
Thin films of the high-temperature superconductor HgBa$_2$CaCu$_2$O$_{6+\delta}$ have been prepared on SrTiO$_3$ substrates by pulsed-laser deposition of precursor films and subsequent annealing in mercury-vapor atmosphere. The…