YBCO yttrium-barium-copper oxide

YBCO - yttrium barium copper oxide PTC - positive temperature coefficient... 

The discovery of high-77 superconductors in the late 1980s led to the need to produce homogeneous and high-purity complex metal oxide species, a need that could be met by the use of sol-gel techniques. The first sol-gel routes to yttrium barium copper oxide (YBCO) involved coprecipitation,222 but latterly, routes based on the hydrolysis and condensation of yttrium and barium alkoxides with copper methoxyethoxide have been developed. It is found that the hydrolysis ratio used in the production of the gel can affect the temperature of the onset of Tc and the sharpness of the transition to superconductivity.223... 

Superconductors are materials that have the ability to conduct electricity without resistance below a critical temperature above absolute zero. The phenomenon of superconductivity was first seen in mercury at liquid helium temperatures. Great interest developed in this area in the late 1980s, when Muller and Bednorz discovered that even ceramic-like materials can exhibit superconductivity. C. W. Chu subsequently found yttrium barium copper oxide (YBCO) to be superconducting above liquid nitrogen temperatures. Indeed, various books are devoted to this subject. > In the following subsections we highlight representative force field applications that have aided the understanding of static and dynamic properties of superconductors. 

YBCO Also known as 1-2-3, YBCO is an acronym commonly used to define the high-temperature superconducting ceramic yttrium-barium-copper oxide, the chemical formula of which has one yttrium, two barium, and three copper atoms (hence 1-2-3). 

Type 11 superconductors are normally limited by the Ginzburg-Landau ratio k = X/ > l/ /l. One special attribute of a high-temperature superconductor (HTS) materials is its small coherence length in comparison with a low-temperature superconductor (LTS), and its anisotropy due to the two-dimensional (2-D) character of the layered crystal structures. The coherence length is on the order of unit cell dimensions, where For example, yttrium barium copper oxide (YBCO)... 

By 1987, superconductivity was observed in another ceramic, yttrium barium copper oxide (YBCO) (YBa CuiOy). Commonly called a 1-2-3 compound because of the 1 2 3 ratio of yttrium to barium to copper. YBCO has a 7 of 93 K (above the temperature of hquid nitrogen). Although 93 K is still cold, it qualifies as quite warm in the world of superconductors, so YBCO is considered to be the first high-temperature superconductor. YBCO was first prepared by combining the three metal carbonates at high temperature (1000 to 1300 K). The copper ions are present in a mixture of -1-2 and 3-3 oxidation states ... 

For example, yttrium barium copper oxide - YBa2 CU3O7 (YBCO), bismuth strontium copper oxide -Bi2Sr2Cu06... 

By 1987, superconductivity was observed in another ceramic, yttrium barium copper oxide (YBCO) (YBa2Cu307). Commonly called a 1-2-3 compound because of the 1 2 3 ratio of yttrium to barium to copper, YBCO has a of 93 K (above the temperature of liquid nitrogen). Although... 

A common feature of all the new ceramic superconductors is that they are cuprates, that is, they are complex copper oxides. The structure of YBCO is given in Fig. 19.3, which also shows that it is related to the perovskite structure (Fig. 4.17). Synthesis of YBCO is remarkably easy appropriate amounts of dry yttrium oxide (Y203), copper oxide (CuO), and barium carbonate (BaC03) are ground together into a fine, well-mixed... 

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