High-temperature superconductors
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.
Dr Jeff Tallon and Dr Bob Buckley with some HTSC wire
Dr Jeff Tallon and Dr Bob Buckley, two of the key scientists behind IRL’s superconductivity research success. In March 1988, Jeff Tallon and Bob Buckley, working at the DSIR laboratories in Wellington (now IRL), correctly identified the structure and composition of a high-temperature superconductivity 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.
High-temperature superconductor research at IRL
How do you make superconductive ceramic wire? How can you improve the electric current carrying capacity of the superconductive ceramic wire? These are just two of the problems that Dr Nick Strickland and his superconductor research team at IRL are investigating. Their focus is on changing the properties of the thin film of superconducting ceramic material present in the wire such that it can carry more electric current and, in particular, more current when a magnetic field is applied.
Acknowledgement:
HTS-110 Ltd
Dr Nick Strickland is a member of the HTS research team based at IRL and also Principal Scientist at Robinson Institute. 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.
HTS110
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.
Superconductors and high-temperature superconductors
In this video, Dr Nick Strickland, a research scientist at IRL, describes the shift that has occurred in the superconductor field from using metal and alloy superconductors that need to be cooled to 4 K to new ceramic superconductors that operate at higher temperatures. By developing ceramic materials that show superconductive properties at temperatures above 77 K (the boiling point of nitrogen), Nick explains some of the economic benefits. This class of superconductor is called ‘high-temperature’, which is a relative term only.
Point of interest
How is liquid nitrogen made?
Acknowledgements:
Artem Topchiy
Bionerd
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 produced and sold state-of-the-art high-field electromagnets that use the HTS wire developed at IRL. In 2011 HTS-110 was acquired by Scott Automation, before becoming an independent company again in 2021, see the HTS110 website.
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.
Useful links
For more on the scientists involved in this research see their profile pages on the Victoria University of Wellington website below:
