Nav: Home

Superconductivity: It's hydrogen's fault

April 27, 2020

Last summer, a new age for high-temperature superconductivity was proclaimed - the nickel age. It was discovered that there are promising superconductors in a special class of materials, the so-called nickelates, which can conduct electric current without any resistance even at high temperatures.

However, it soon became apparent that these initially spectacular results from Stanford could not be reproduced by other research groups. TU Wien (Vienna) has now found the reason for this: In some nickelates additional hydrogen atoms are incorporated into the material structure. This completely changes the electrical behaviour of the material. In the production of the new superconductors, this effect must now be taken into account.

The search for High-Temperature Superconductors

Some materials are only superconducting near absolute temperature zero - such superconductors are not suitable for technical applications. Therefore, for decades, people have been looking for materials that remain superconducting even at higher temperatures. In the 1980s, "high-temperature superconductors" were discovered. What is referred to as "high temperatures" in this context, however, is still very cold: even high-temperature superconductors must be cooled strongly in order to obtain their superconducting properties. Therefore, the search for new superconductors at even higher temperatures continues.

"For a long time, special attention was paid to so-called cuprates, i.e. compounds containing copper. This is why we also speak of the copper age", explains Prof. Karsten Held from the Institute of Solid State Physics at TU Wien. "With these cuprates, some important progress was made, even though there are still many open questions in the theory of high-temperature superconductivity today".

But for some time now, other possibilities have also been under consideration. There was already a so-called "iron age" based on iron-containing superconductors. In summer 2019, the research group of Harold Y. Hwang's research group from Stanford then succeeded in demonstrating high-temperature superconductivity in nickelates. "Based on our calculations, we already proposed nickelates as superconductors 10 years ago, but they were somewhat different from the ones that have now been discovered. They are related to cuprates, but contain nickel instead of copper atoms," says Karsten Held.

The Trouble with Hydrogen

After some initial enthusiasm, however, it has become apparent in recent months that nickelate superconductors are more difficult to produce than initially thought. Other research groups reported that their nickelates do not have superconducting properties. This apparent contradiction has now been clarified at TU Wien.

"We analysed the nickelates with the help of supercomputers and found that they are extremely receptive to hydrogen into the material," reports Liang Si (TU Vienna). In the synthesis of certain nickelates, hydrogen atoms can be incorporated, which completely changes the electronic properties of the material. "However, this does not happen with all nickelates," says Liang Si, "Our calculations show that for most of them, it is energetically more favourable to incorporate hydrogen, but not for the nickelates from Stanford. Even small changes in the synthesis conditions can make a difference." Last Friday (on 24.04.2020) the group around Ariando Ariando from the NUS Singapore could report that they also succeeded in producing superconducting nickelates. They let the hydrogen that is released in the production process escape immediately.

Calculating the Critical Temperature with Supercomputers

At TU Wien new computer calculation methods are being developed and used to understand and predict the properties of nickelates. "Since a large number of quantum-physical particles always play a role here at the same time, the calculations are extremely complex," says Liang Si, "But by combining different methods, we are now even able to estimate the critical temperature up to which the various materials are superconducting. Such reliable calculations have not been possible before." In particular, the team at TU Wien was able to calculate the allowed range of strontium concentration for which the nickelates are superconducting - and this prediction has now been confirmed in experiment.

"High-temperature superconductivity is an extremely complex and difficult field of research," says Karsten Held. "The new nickelate superconductors, together with our theoretical understanding and the predictive power of computer calculations, open up a whole new perspective on the great dream of solid state physics: a superconductor at ambient temperature that hence works without any cooling."
-end-
Contact

Prof. Karsten Held
Institute for Solid State Physics
TU Wien
Wiedner Hauptstraße 8-10, 1040 Vienna
T +43-1-58801-13710
karsten.held@tuwien.ac.at

Vienna University of Technology

Related Hydrogen Articles:

Hydrogen vehicles might soon become the global norm
Roughly one billion cars and trucks zoom about the world's roadways.
Hydrogen economy with mass production of high-purity hydrogen from ammonia
The Korea Institute of Science and Technology (KIST) has made an announcement about the technology to extract high-purity hydrogen from ammonia and generate electric power in conjunction with a fuel cell developed by a team led by Young Suk Jo and Chang Won Yoon from the Center for Hydrogen and Fuel Cell Research.
Superconductivity: It's hydrogen's fault
Last summer, it was discovered that there are promising superconductors in a special class of materials, the so-called nickelates.
Hydrogen energy at the root of life
A team of international researchers in Germany, France and Japan is making progress on answering the question of the origin of life.
Hydrogen alarm for remote hydrogen leak detection
Tomsk Polytechnic University jointly with the University of Chemistry and Technology of Prague proposed new sensors based on widely available optical fiber to ensure accurate detection of hydrogen molecules in the air.
Preparing for the hydrogen economy
In a world first, University of Sydney researchers have found evidence of how hydrogen causes embrittlement of steels.
Hydrogen boride nanosheets: A promising material for hydrogen carrier
Researchers at Tokyo Institute of Technology, University of Tsukuba, and colleagues in Japan report a promising hydrogen carrier in the form of hydrogen boride nanosheets.
World's fastest hydrogen sensor could pave the way for clean hydrogen energy
Hydrogen is a clean and renewable energy carrier that can power vehicles, with water as the only emission.
Chemical hydrogen storage system
Hydrogen is a highly attractive, but also highly explosive energy carrier, which requires safe, lightweight and cheap storage as well as transportation systems.
Observing hydrogen's effects in metal
Microscopy technique could help researchers design safer reactor vessels or hydrogen storage tanks.
More Hydrogen News and Hydrogen Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.