Superconductors carry record current flow

Cambridge University researchers have made a breakthrough in the manufacture of high-temperature superconducting materials, producing samples claimed to carry record quantities of electrical current.

Prof David Caldwell and his team have produced samples of high-temperature superconducting yttrium barium copper oxide (YBCO) using a new technique for fabricating large, single grains of bulk superconductors.

Currently, producing YBCO superconductors is a complex and expensive process, as it must be done in a single grain in order to generate large magnetic fields, since boundaries between grains limit the flow of current in the bulk sample.

Similarly, microscopic defects within the material can impede the motion of magnetic flux lines and increase the flow of current through it. The distribution of these lines within a bulk superconductor has to be managed to maximise the flow of current and, therefore, the field.

‘Our process for making larger crystals is fairly spectacular,’ said Caldwell. ‘We have a sample and we have a seed crystal on the top. We physically melt the material and then we cool it down and a single grain grows from that crystal. What we’re left with is something like a hockey puck, around 4cm in diameter.’

Register now to continue reading

Thanks for visiting The Engineer. You’ve now reached your monthly limit of news stories. Register for free to unlock unlimited access to all of our news coverage, as well as premium content including opinion, in-depth features and special reports.  

Benefits of registering

  • In-depth insights and coverage of key emerging trends

  • Unrestricted access to special reports throughout the year

  • Daily technology news delivered straight to your inbox