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AMN8 2017February 13, 2017

AMN8 Queenstown: talking superconductor sandwiches at 25,000 feet


Charles Anderson is in Queenstown for AMN8 – the advanced materials and nanotechnology conference hosted by The MacDiarmid Institute. In his first blog from the event, he enjoys a heaven-sent introduction to the field from Ben Mallett on the flight south.

The flight from Christchurch to Queenstown is full, says the cabin attendant. But as the young man sporting the sandals, white rimmed glasses and several days’ stubble sits down, there is still plenty of room.

There is a nod of acknowledgement. And then, the small talk. Usually on planes this is confined to the basics of one’s day, one’s imminent plans. But today it evolves into a world I know next to nothing about – solid state physics.

“What brings you to Queenstown?” he asks.

“I’m heading to a conference in a field that I don’t really have any idea about,” I answer.


He could have been a backpacker but it turns out that Ben Mallett is a doctor of physics, who is based in Auckland as the Rutherford postdoctoral fellow.

AMN8 is the yearly conference organised by the MacDiarmid Institute, which brings together 500 scientists from around the country and from 35 countries around world to discuss the latest developments in the fields of nano and materials science.

I am here to try and bring some insight into a world little seen or understood beyond those in the science circles. I am an outsider trying to relate this world to a greater New Zealand population.

For the past several weeks I have interviewed several scientists who will be speaking at this conference.

Their work ranges from understanding how nano sized particles can be used to better deliver chemotherapy to cancerous cells to changing the future of the energy sector by developing efficient solar panels out of newly discovered materials.

Read Charles Anderson’s interviews with AMN8 attending scientists:
Zoom in. Keep zooming. Don’t stop. On New Zealand and the nano-revolution
Unpeeling the nano onion: Silvia Giordani on the potential for a massive, tiny breakthrough in cancer treatment
Henry Snaith: how a miracle mineral may hold the key to a solar energy revolution
Amanda Barnard: how tiny diamonds could forever change the face of medicine
Rachel Segalman and the incredible possibilities of the new thermopower generation

So Ben is an ideal soft introduction to this world. He is generous with his explanations and unintimidating. He is on a budget and when we land will be checking into a bed and breakfast out of town. He hopes to rent a bike and cycle into the conference each day.

As we pass over the Southern Alps, Ben says events like AMN8 are invaluable to scientists. They can bring people together who may be working on different problems but could bring insights to each other’s work.

His work, he explains, is with superconductors – materials that can conduct electricity with zero resistance.

In normal conducting materials an electrical current always faces resistance. This creates not only wastage but potential disaster if a material gets too hot. So superconductors open up a world of possibilities, Ben says.

“This means you can do things with them you can’t do with normal metals – you can only do them with these materials.”

One example is MRI machines.

“The way they take an image is that they need a strong magnetic field.”

The way you create that is not with normal magnets but with a coil of wire that is charged with a “dirty big current”, as Ben puts it.

If you did this with normal conducting materials the whole thing would melt. So instead a superconducting wire is used.

Inflight nano-instructor: Ben Mallett. Photo: Charles Anderson

Normal conducting metals work better when they are cooled. But even when they are cooled to their lowest possible point they will still have some resistance.

The resistance of a superconductor, on the other hand, will drop to zero when it is cooled to certain point. An electric current flowing through a loop of superconducting wire can persist indefinitely with no power source.

But to cool normal superconducting materials is very expensive. To do this scientists use liquid helium – a non renewable resource which is running out.

So Ben has started working with another superconducting material which is less well known. It doesn’t need cooling down as much.

Named the particularly unexciting YBCO (which relates to the elements it incorporates in the periodic table), it can carry a very large current and can work at a very high temperature.  These are two of the key characteristics of an effective superconductor. It is also relatively stable, non toxic and all its materials are relatively easy to come by.

But what Ben has started to do is experiment with the material by sandwiching it between two slices of magnetic material.

“When you sandwich it together then you get some completely new behaviour in the superconductor. It’s like if you have bread that’s sitting by itself and some ham alongside it but then when you put together you get something completely new.”

It becomes a superconducting sandwich.

In this formation YBCO becomes a better superconductor in a magnetic field.

“That’s never been seen before.”

It also becomes a better superconductor in an electrical current.

“That too hasn’t been seen before,” Ben says. “It’s exciting and asking to be explained and used.”

As we land he talks about how his work could be applied to the real world. It could be applicable, for example, to next generation giant wind turbines that need smaller motors to power them or else they might topple over. But while he has those sorts of visions in mind he knows that it is a long road before any innovative science becomes ubiquitous in the real world.

His real concern is that science is answering problems that the real world has.

“There is no point in doing science that people don’t need,” he says. “Sometimes I think there is a gap between what we do and what the real world needs. We need to get better at understanding that.”

We part ways at the airport but a short while later I see him at the conference venue. He found a bike.

This is part of a series of articles for the Spinoff about and from AMN8, The Eighth International Conference on Advanced Materials and Nanotechnology, in Queenstown from February 12-16 2017. For details on public events in Christchurch, Wanaka, Queenstown and Nelson, click here. This content series is sponsored by the conference’s hosts, The MacDiarmid Institute for Advanced Materials and Nanotechnology, a national institute devoted to scientific research.


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