Grain boundary misorientations and percolative current paths in high-J c powder-in-tube (Bi,Pb)2Sr3Ca3Cu3Ox

Abstract

Properties and chemical stability of hotrolled Ag(7 at.% Cu)sheathed Bi2Sr2Ca0.64Cu1.64O x powderintube tapes

Iron chalcogenide superconductors at high magnetic fields

“…PIT technique has been used widely in Bi-based cuprate oxide wires (first-generation high-temperature superconductor (HTS) wires) and MgB 2 [85,86]. Ozaki et al [87] fabricated Fe(Se,Te) wires by an ex situ PIT method with the transport J c (0) of about 64 A cm −2 at 4.2 K. Recently, chemical-transformation PIT method was used to fabricate FeSe wires with a transport J c (0) of 588 A cm 2 at 4.2 K for a three-core wire ( figure 9(a)) [88].…”

Preparation and Thermoelectric Property of Highly Oriented Al-Doped ZnO Ceramics by a High Magnetic Field

“…[1][2][3][4][5][6] However, these thermoelectric oxides in polycrystalline are a much smaller electrical conductivity than that of the single crystals because the electrical conductivity is greatly influenced by the misorientation angles between the nearest neighboring grains, and thus this hinders a practical application. 7) In the case of oriented Al-doped ZnO thin films with large crystallite sizes, the films have the electrical conductivity as high as 2000 S/cm, which is almost five times larger than that of non-oriented polycrystalline bulk with the same composition. 8) In addition to this, the electron mobility of non-doped single crystal of ZnO has been reported around 200 cm 2 V À1 s À1 whereas the mobility of non-oriented polycrystalline Al-doped ZnO bulk is around 40 -50 cm 2 V À1 s À1 .…”

2D and 3D percolation in high-temperature superconductors

“…A final possibility for J c greater than predicted by the percolative model is that low-angle boundaries may occur with greater frequency than dictated by chance alone; i.e., local orientational order may occur. 16 …”

“…16 Here we present a quantitative percolative model which explains how large J c can be observed in materials in which only a small fraction f of the grain boundaries are small angle. We assume that j c is large when grainboundary misorientation is below c of 10°to 20°, independent of other aspects of grain-boundary geometry: this is consistent with all available data.…”