Ceramic Superconductors Wiki

Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material.

Ceramic superconductors wiki.

The yttrium compound is somewhat unique in that it has a regular crystal structure while the lanthanum version is classified as a solid solution. Any material exhibiting these properties is a superconductor unlike an ordinary metallic conductor whose resistance decreases gradually as its temperature is lowered even down to near absolute zero a superconductor has a. Yba 2 cu 3 o 7 x was the first ceramic superconductor discovered with t c greater than liquid nitrogen temperature. This superconductor has a critical transition temperature around 90k well above liquid nitrogen s 77k.

The temperature at which resistance ceases is referred to as the transition temperature or critical temperature tc. The ceramic superconductors are also called high temperature or liquid nitrogen temperature superconductors. The superconductor we will be experimenting with is an yttrium y barium ba and copper cu composition. The high temperature superconductors are ceramic materials with layers of copper oxide spaced by layers containing barium and other atoms.

Superconductivity is the complete disappearance of electric resistance in materials that are cooled to extremely low temperatures. Opened up the possibilities for new superconductors. A ceramic superconductor was discovered by alex müller and georg bednorz. Because liquid nitrogen is relatively inexpensive and easier to handle there is a greater interest in the ceramic superconductor machines than the liquid helium cooled metal superconductor machines.

Tc is usually measured in degrees kelvin k 0 k being absolute zero the. X y means material x doped with element y t c is the highest reported transition temperature in kelvins and h c is a critical magnetic field in tesla. The yttrium compound is often called the 1 2 3 superconductor because of the ratios of its constituents. Many ceramic superconductors physically behave as superconductors of the second type.

The ceramic materials used to make superconductors are a class of materials called perovskites. Yttrium barium copper oxide ybco is a family of crystalline chemical compounds famous for displaying high temperature superconductivity it includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen 77 k at about 92 k many ybco compounds have the general formula y ba 2 cu 3 o 7 x also known as y123 although materials with other y. Conductive ceramics conductive ceramics superconductors. A lanthanum barium copper and oxygen compound with a critical temperature of 30k.

Ceramics are normally insulators. Bcs means whether or not the superconductivity is explained within the bcs theory. Chemical formula is yba2cu3o7. The first high temperature superconductor was discovered in 1986 by ibm researchers bednorz and müller 3 6 who were awarded the nobel prize in physics in 1987 for their important break through in the discovery of superconductivity in ceramic materials.