A phenomenal pairing

Dr Bob Buckley (left) and Dr Jeff Tallon: New Zealand science legends.

It’s almost 25 years since Drs Bob Buckley and Jeff Tallon first heard the astonishing news that the mysterious phenomenon called superconductivity had been discovered in a ceramic at temperatures far higher than previously thought possible. 

This remarkable effect, in which some materials lose all electrical resistance, had once upon a time only been observed at temperatures as cold as outer space; this new threshold however was higher than the temperature of liquid nitrogen (-196 degrees Celsius or 77 Kelvin), a cheaply available coolant. The commercial potential this opened up was breathtaking. 

Then it was Drs Buckley and Tallon’s turn to astonish the science world, when they won the international race to identify a new wonder ceramic that was observed to produce the  same superconducting effect at the even higher temperature of -163ºC (110K). That they were also the ones to patent the formula is one of New Zealand’s science legends. It was a time of intense excitement. 

Since then, Dr Buckley and Dr Tallon have patiently and single-mindedly pursued the goal of complete understanding of this phenomenon of high-temperature superconductivity, and have developed an array of applications for both new and existing magnetic and electrical devices, such as MRI^[?] medical scanners and transformers.

Dr Tallon is building the theory through a comprehensive  experimental programme, while Dr Buckley leads the team of more than 20 at IRL Gracefield, set on solving the technological problems associated with a fundamentally different, brittle  conducting material that has to be kept at the right  temperature. (The ‘high-temperature’ descriptor is  somewhat misleading — 110K is still 163ºC below the freezing point of water.) 

The pair’s research partnership has outlasted governments, restructurings, name changes and funding fashions. They’ve lost count of the grant applications, the reviews, the talks and the  interviews where they must explain, yet again, just how they felt to people who cannot really understand the quantum behaviour behind the incredibly complicated electron interactions that  underpin superconductivity. The Marsden Fund grant application Dr Tallon put in recently — and  received — is aptly titled ‘Quantum Soup’. 

A number of conditions have to be satisfied at  the critical temperature at which superconductivity sets in. Here, the electrons abruptly transform from a chaotic rabble, dragged along by the electromagnetic field, into orderly pairs moving coherently in the same quantum state. From rock and roll to Viennese waltz. 

Although these ceramic superconductors seem to behave quite differently from traditional low-temperature superconductors, as far as the relationship between the superconducting  transition temperature and other parameters are concerned, Dr Tallon’s achievement has been to see that they are no different — the relationship is just disguised. However the great mystery as to why the electrons pair up remains. (In low-temperature superconductors it is understood that the pairing is prompted by vibration of the atoms.) 

When asked if investors’ expectations of turning the science into gold are uncomfortable at times, Dr Buckley says it has not been “a negative pressure”. At each stage, they have had a clear direction and simply concentrated on the next step. The flashes of insight are interspersed by ‘head down’ periods  of slower tempo, and some inevitable dead ends. Scientists understand and accept that the timescales for these developments are counted in decades. 

Although the euphoria of cracking the structure of the 110K superconducting ceramic was a once-in-a-lifetime thrill, the formation of the company HTS-110^[?] Ltd and sales of products such as the first dipole magnet to Brookhaven National Laboratory in New York continue to give “a terrific buzz”, says Dr Tallon. The most nerve-wracking period, apart from worrying about another team beating them to the magic HTS^[?] formula, was hanging onto the patents through repeated legal challenges. The whole undertaking, particularly the crucial business relationship with American Superconductor Corporation, was at risk.

It’s been a long-haul journey. Medals they have aplenty, but the recent award of the inaugural Prime Minister’s Science Prize to both Dr Buckley and Dr Tallon has been a great encouragement to them personally and to the whole team.

The future of the technology looks ever brighter as concerns about energy and the environment favour these new superconductors that offer a broad range of smaller, lighter, more powerful and efficient electrical products. 

About high-temperature superconductivity

Superconductivity is a phenomenon where some materials conduct electricity with no resistance or energy loss during the transmission process. While it would seem that high-temperature superconducting cables are very hot, they are in fact extremely cold and are termed high-temperature because they are comparatively much warmer than previously developed low-temperature superconducting materials, which operated at close to absolute zero — the temperature of  liquid helium (-73 degrees Celsius).

HTS technology operates at the relatively warmer temperatures of liquid nitrogen (-196ºC). The colder the materials are, the greater the financial cost, so the development of HTS makes superconducting technology a viable commercial proposition.