In March 1988, New Zealand scientists Dr Jeff Tallon and Dr Bob Buckley, working at the DSIR laboratories in Wellington (now known as IRL), correctly identified the structure and composition of an exceptionally high-performing ceramic compound.
In 2010 Dr Jeff Tallon and Dr Bob Buckley were jointly awarded the inaugural Prime Minister’s Science Prize, Find out more here.
The material is a metal oxide consisting of bismuth, lead, strontium, calcium, copper and oxygen – known as BSCCO-2223. It becomes superconductive at -163°C, which, in everyday life, is extremely low but is referred to as ‘high temperature’ in the superconductor world.
Today, this material is the only substance being used commercially in the world for the production of high-temperature superconductor (HTS) wire. The HTS wire is made up of a nickel/tungsten alloy base upon which is placed a very thin film of the superconductor ceramic. It is this thin layer (1 micron thick) of ceramic that carries the current when cooled to -163°C.
Dr Nick Strickland is a member of the HTS research team based at IRL. One of his research projects is to investigate changing the properties of the ceramic film so that it can carry even more current – in particular, more current when a magnetic field is applied.
High-temperature superconductors can be used to replace the conventional copper wires found in the windings of electromagnets, electric motors and electric generators.
The coolant traditionally used in superconductive systems is liquid helium. By developing advanced ceramics that become superconductive at higher temperatures, a switch can be made from expensive liquid helium to cheaper liquid nitrogen as coolant. This makes for huge savings in operational costs.
Research at IRL is primarily focused on creating wealth for New Zealand. Part of Nick’s job is to develop HTS science into a technological application and push it towards the marketplace.
Currently, Nick is part of a team of about 20 researching the high-temperature superconductors and has 2–3 scientists reporting to him. Together, they use a range of electrical, magnetic, structural and microscopy techniques to study high-temperature superconducting ceramic materials that have been made under slightly different conditions.
A start-up company – HTS110 – grew up out of the HTS research group at IRL and is now producing and selling state-of-the-art high-field electromagnets that use the HTS wire developed at IRL.
Nature of science
Scientific discoveries often have a technological application. The time lag between making the discovery and finally entering the market place is often many years.
Watch a video of the July 2014 Ten by Ten talk by Dr Jeff Tallon, outlining how New Zealand scientists have been pivotal in the slow task of making superconductors more practical: finding materials that superconduct at significantly higher temperatures, making superconducting wires less brittle, and helping us understand the complex physics involved.