Ask an Expert: Ask Putting the ‘super’ in superconductors with Grace Pan
How can you tell that Superman is a superhero? Well – the clue is in the name. Anyone called Superman is unlikely to be a regular Joe, and the same is true of superconductors.
From Magnetic Resonance Imaging (MRI) machines to the Large Hadron Collider (LHC), and high-speed transportation prototypes, these over-achieving conductors are behind many incredible technologies today. These superconductor materials expel the magnetic field, allowing a current to move through them with zero electrical resistance, meaning that once generated, the current flows continuously at 100% efficiency.
There’s just one problem: superconductor materials only operate at extreme temperatures or pressures. It’s incredibly expensive and energy-intensive to create these extreme conditions, which prohibits the widespread application of superconductors despite how useful they are.
But imagine what it would mean if we could harness superconductors at room temperature and standard pressure. The applications would be almost endless, from greatly increasing the lifespan of our electronic devices, to revolutionizing the world’s energy system. For example – imagine solar panel farms that can store and transmit energy at a 0% loss, powering entire cities and dramatically reducing greenhouse gas emissions.
Superconductivity: the ‘Holy Grail’ of materials research
Identifying quantum materials that could act as superconductors under everyday conditions is fundamental to advancing the practical application of superconductivity. Luckily, there are a lot of very smart scientists on the case already.
When it comes to a suitable materials platform, one of the prime candidates is rare-earth nickelates. In fact, superconductivity was recently discovered in the doped compound Nd0.8Sr0.2NiO2.
Grace and the Empyrean
Enter Grace Pan: a Ph.D. student at Harvard University, who spearheaded a study into how we can design and synthesize new superconductors at the atomic scale using molecular beam epitaxy (MBE).
MBE creates a single crystal by building up orderly layers of molecules on top of a base layer. It enables atomic-layer-by-atomic-layer control over inorganic materials synthesis.
In tandem with characterization techniques, including electronic transport, synchrotron spectroscopies, and X-ray diffraction (XRD) using the Malvern Panalytical Empyrean, Grace used MBE to create a new, layered nickel oxide-based superconductor.
Square-planar nickelates: a new family of superconductors
Using reactive oxide MBE, Grace designed and synthesized the five-layer (n = 5) member of this particular series of layered square-planar nickelates: Nd6Ni5O12. This unique compound achieves optimal cuprate-like electron filling without chemical doping, with a superconducting transition beginning at ~13 K.
Electronic structure calculations, along with magnetoresistive and spectroscopic measurements, suggest that Nd6Ni5O12 interpolates between cuprate-like and infinite-layer nickelate-like behavior. By engineering this distinct superconducting nickelate, Grace has identified the square-planar nickelates as a new family of superconductors, which can be tuned via doping and dimensionality.
No wonder, then, that Grace’s paper on ‘Superconductivity in a quintuple-layer square-planar nickelate’ was named winner of the 2022 Malvern Panalytical Scientific Award! We were fascinated to read her paper, and you can take a look for yourself here. But that’s not all…
Hear from Grace herself on April 20
Grace is presenting her fascinating work as a guest speaker at our upcoming Ask an Expert! webinar on April 20! She’ll give a deep-dive into what quantum materials are, give us a background into the design principles behind unconventional superconductors, and – of course – answer all your questions.
If you already have a question, submit it in advance to askanexpert@malvernpanalytical.com – or just bring it along for our expert to answer on the day. We look forward to seeing you there.
Register now and reserve your place on April 20!
Can’t wait that long? Catch up on past webinars and check out upcoming ones here.
Check out the Empyrean instrument used in this research here.