UK physicists defy the weakest link

Researchers at Cambridge University reveal today that the newly discovered superconducting material magnesium borate has properties that will have exciting implications for its use as a conductor and a high field generating device. This first insight into the amazing material is published today in the Institute of Physics journal, Superconductor Science and Technology.

Until the late 1980's accepted theory suggested that superconductors could not exist above -240 degrees centigrade 30 Kelvin. However, a generation of new so-called High Temperature SuperConductors was discovered in 1987, which were developed to superconduct at -107 degrees centigrade 166 Kelvin. The higher the electrical currents that a superconductor can carry at a given temperature, the greater its potential for use in everyday life. Superconductors are used for a variety of applications including MRI scanners and energy storage devices of the type used on the underground to supply a steady flow of power to the trains.

Many of the high temperature superconductors have serious drawbacks, however. These materials are very complex metal oxides that behave like ceramics - they are granular and very brittle. When made into wires or other useful materials, it becomes very difficult to pass current from one grain to the next. These grain boundaries are effectively weak links to the flow of electric current, severely limiting the application potential of the materials.

Work by Dr David Cardwell and colleagues in Cambridge on the recently discovered material magnesium borate, reveals that the grain boundaries in this case do not form weak links to the flow of current. This material also overcomes another problem many superconductors have - it is not particularly sensitive to the application of a magnetic field.

"This is a major breakthrough in this field and has exciting implications for potential applications as both a conductor and a high field generating device", said Dr Cardwell.

Notes for Editors

1. For further information on this research please contact Dr. David Cardwell, Interdisciplinary Research Centre in Superconductivity, Cambridge University, Telephone :01223-337050, Fax: 01223-337074, E-mail:

This research is published in Superconductor Science and Technology, Vol 14, issue 4, L5-L7, http://www.iop.org/EJ/S/2/IOPP/UZ5.X5Md4bmgsyiLwEVOGA/toc/0953-2048/14/4

2. Superconductor Science and Technology is published by Institute of Physics Publishing, a wholly owned subsidiary of the Institute of Physics. For further information on this please contact: Nina Couzin, Tel: 011-7930-1068, Fax: 011-7929-4, Email: [email protected]

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