Single grain boundaries

The effect of the two types of boundary on the measurements of resistivity vs. temperature are shown in Fig. 12.21. None of the leads, the c-axis material and the a-axis material measured in the [010] and [001] directions, shows ideal behavior. This is, at least in part because of the necessity of some compromise in the deposition temperature between ideal a-axis and c-axis conditions. However, the results for the twist grain boundary are consistent with that found previously for (103) films measured across many such grain boundaries there 

Facetting of the twist boundary must also be considered. In this case, BPF and symmetrical tilt facets do not intersect the macroscopic current path. Since we already have indication from the (103) films that the twist boundary does not degrade current, we do not expect that indirect paths crossing these boundaries will be preferred. However, when the nominal twist boundary deviates from its macroscopic direction it may form (110)(103) facets which do 

Investigations on the microstructure of YBa2Cu307 thin-film edge Josephson junctions by high-resolution electron microscopy 

The discovery of cuprates exhibiting superconductivity at relatively high temperatures has opened up new prospects for the application of superconductivity in many areas, in particular in sensor systems and in electronics [13.1, 

In this respect the superconducting quantum interference device (SQUID) is one of the most attractive developments. Many different designs have been fabricated and studied, and modem SQUIDs on the basis of YBa2Cu307 have reached field sensitivity and performance levels not far different from those known for devices produced with classical low temperature superconductors [13.3, 13.4]. 

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Hurley, D. H Wright, O. B., Matsuda, O., Suzuki, T., Tamura, S., and Sugawara, Y. (2006). Time-resolved surface acoustic wave propagation across a single grain boundary. Physical Review B 73,125403. [254]... 

Fig. 9.38. Schematic of increasingly complex grain boundary distributions within materials (adapted from Randle (1994)) (a) bicrystal geometry with a single grain boundary, (b) bamboo-like distribution of grain boundaries in a one-dimensional array, (c) polycrystalline film, and (d) three-dimensional polycrystal.

The bicrystal single grain boundary Josephson junction is fabricated by depositing an epitaxial c-axis oriented cuprate film on a substrate bicrystal... 

Fig. 12.20. Fabrication of single grain boundaries. The lines indicate the CuOg planes of the aligned a-axis region on a PBCO buffer layer and the shaded areas show the c-axis region on the bare substrate. The black pattern is the photolithographic mask used for defining the four measurement lines the BPF and the twist grain boundaries, and the [010] and [001] leads in the a-axis film.

Fig. 12.22. Critical current density of the two single grain boundaries of the twist boundary is comparable to the [010] lead of the aligned a-axis material, whereas of the BPF boundary is lower than that of the [001] lead.

Fig. 5-8, Geometry (a) and concentration contours (b) of a solid with a single grain boundary perpendicular to the x-axis and a constant concentration source.

According to measurements of resistance-temperature characteristics across single grain boundaries, the PTC characteristic differs from grain boundary to grain boundary, as shown in Figures 2.1.3 and 2.1.4. The drastic resistance... 

FIGURE 2.1.3 Sample for measurement of PTC characteristics across single grain boundary [4]. 

FIGURE 2.1.4 Typical three different PTC characteristics across single grain boundaries [6]. 

Matsunaga, T., Shimooka, H., Takahashi, S., and Kuwabara, M. (1993). Or mizations and PTCR characteristics of single grain boundaries in barium titanate ceramics. Proceedings of Fall Meeting of The Ceramic Society of Japan, p. 276. 

Fleig, J., Rodewald, S., and Maier, J. (2000). Spatially resolved measurements of single grain boundaries using microcontact impedance spectroscopy. Solid State Ionics 133 903-912. 

Grain-Boundary Conductivity, Fig. 4 A log-log plot of the current-voltage curve measured for a single grain boundary in 2 mol% Y-doped BaZrOs at 350 °C [15]... 

The simplest model of grain growth considers the movement of a single grain boundary in a pure, dense material. There is a free energy difference AG across a curved grain boundary ... 

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