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Primeur weekly 2019-02-18

Focus

2018 - Another year on the Road to Exascale - Part III - Software and applications ...

EOSCpilot science demonstrators boost follow-up initiatives in federating European Open Science Cloud concept ...

Quantum computing

Questions in quantum computing: How to move electrons with light ...

Focus on Europe

Arm SVE Hackathon to focus on Arm Scalable Performance for HPC and ML ...

EuroHPC Summit Week 2019: PRACEdays19 Call for Contributions and Posters is open ...

PRACE Ada Lovelace Award nominations open ...

Middleware

Bright Computing selects XENON as an Asia Pacific Services Partner ...

Hardware

RIKEN issues call for proposals for the name of the post-K ...

Fujitsu receives order for massively parallel supercomputer system called Oakbridge-CX from the University of Tokyo ...

Cray reports 2018 full year and fourth quarter financial results ...

South African Weather Center doubles computing and triples storage system capacities with Cray ...

WekaIO Matrix cements its storage leadership with groundbreaking performance and latency results on SPEC SFS 2014 ...

NERSC tape archives make the move to Berkeley Lab's Shyh Wang Hall ...

NVIDIA announces financial results for fourth quarter and fiscal 2019 ...

Applications

CERIC-ERIC call for proposals is now open ...

CalTech researcher uses Blue Waters to model galactic atmospheres ...

Six research groups awarded new GLCPC allocations on Blue Waters supercomputer ...

Visualizing biomedical breakthroughs in data ...

Theories describe dynamically disordered solid materials ...

Dark fiber lays groundwork for long-distance earthquake detection and groundwater mapping ...

Vanderbilt University Medical Center researchers, supercomputing effort reveal antibody secrets ...

ORNL teams with Los Alamos and EPB to demonstrate next-generation grid security tech ...

The Cloud

IBM Watson now available anywhere ...

Theories describe dynamically disordered solid materials


Johan Klarbring. Credit: Thor Balkhed.
11 Feb 2019 Linkoping - Theoretical physicists at Linköping University (LiU) have developed a computational method to calculate the transition from one phase to another in dynamically disordered solid materials. This is a class of materials that can be used in many eco-friendly applications.

Solid materials are in reality not quite as solid as they appear. Normally, each atom actually vibrates around a certain position in the material. Most theoretical models that aim to describe solid materials are based on the assumption that the atoms retain their positions and do not move very far from them.

"This is not the case for some materials, such as materials with very high ionic conductivity and those where the building blocks are not only atoms but also molecules. Several of the perovskites that are promising materials for solar cells are of this kind", Johan Klarbring, doctoral student in theoretical physics at Linköping University, stated.

Perovskites are defined by their crystal structures and come in different forms. Their constituents can be both atoms and molecules. The atoms in the molecules vibrate, but the complete molecule can also rotate, which means that the atoms move significantly more than is often assumed in the calculations.

Materials that show this atypical behaviour are known as "dynamically disordered solid materials". Dynamically disordered solid materials show immense potential in environmentally sensitive applications. Materials that are good ionic conductors are, for example, promising in the development of solid electrolytes for batteries and fuel cells, and for thermo-electric applications.

However, the properties of materials have been tricky to calculate theoretically and researchers have often been forced to use time-consuming experiments.

Jonas Klarbring has developed a computational method that describes accurately what happens when these types of material are heated and undergo phase transitions. Johan Klarbring and his supervisor, Professor Sergei Simak, have published the results in the scientific journalPhysical Review Letters.

They have studied bismuth oxide, Bi2O3, a material known to be a very good ionic conductor. This oxide, where current is conducted by oxide ions, is the best oxide ion conductor of all known solid materials. Experiments have shown that it has a low conductivity at low temperatures, but when heated it undergoes a phase transition into a dynamically disordered phase with high ionic conductivity.

"The article inPhysical Review Lettersdescribes how we have been able for the first time to theoretically describe the phase transition in bismuth oxide, and calculate the temperature at which it occurs. This provides an important theoretical basis for the development of, for example, electrolytes in fuel cells, where it is important to know exactly when the phase transition takes place", stated Johan Klarbring.

"I start from an ordered phase, which is well-described by conventional methods. I then use a technique known as 'thermodynamic integration', which I have adapted to deal with the disordered motion. The ordered phase is coupled to the disordered one, with the aid of a series of quantum mechanical calculations, carried out at the National Supercomputer Centre at LiU."

The theoretical calculations are in full agreement with how the material behaves in laboratory experiments.

The researchers now plan to test the method on other interesting materials, such as perovskites, and on materials with high lithium ionic conductivity. The latter are of interest for the development of high-performance batteries.

"Once we have a deep theoretical understanding of the materials, it improves the possibilities to optimise them for specific applications", concluded Johan Klarbring.

The research is financed by the Swedish Research Council and the Swedish Government Strategic Research Area initiative in Material Science on Functional Materials at Linköping University.

The paper titled " Phase Stability of Dynamically Disordered Solids from First Principles " is authored by Johan Klarbring and Sergei I. Simak, both from Linköping University. It has appeared inPhysical Review Letters121, 2018 - DOI 10.1103/PhysRevLett.121.225702.

Source: University of Linkoping

Back to Table of contents

Primeur weekly 2019-02-18

Focus

2018 - Another year on the Road to Exascale - Part III - Software and applications ...

EOSCpilot science demonstrators boost follow-up initiatives in federating European Open Science Cloud concept ...

Quantum computing

Questions in quantum computing: How to move electrons with light ...

Focus on Europe

Arm SVE Hackathon to focus on Arm Scalable Performance for HPC and ML ...

EuroHPC Summit Week 2019: PRACEdays19 Call for Contributions and Posters is open ...

PRACE Ada Lovelace Award nominations open ...

Middleware

Bright Computing selects XENON as an Asia Pacific Services Partner ...

Hardware

RIKEN issues call for proposals for the name of the post-K ...

Fujitsu receives order for massively parallel supercomputer system called Oakbridge-CX from the University of Tokyo ...

Cray reports 2018 full year and fourth quarter financial results ...

South African Weather Center doubles computing and triples storage system capacities with Cray ...

WekaIO Matrix cements its storage leadership with groundbreaking performance and latency results on SPEC SFS 2014 ...

NERSC tape archives make the move to Berkeley Lab's Shyh Wang Hall ...

NVIDIA announces financial results for fourth quarter and fiscal 2019 ...

Applications

CERIC-ERIC call for proposals is now open ...

CalTech researcher uses Blue Waters to model galactic atmospheres ...

Six research groups awarded new GLCPC allocations on Blue Waters supercomputer ...

Visualizing biomedical breakthroughs in data ...

Theories describe dynamically disordered solid materials ...

Dark fiber lays groundwork for long-distance earthquake detection and groundwater mapping ...

Vanderbilt University Medical Center researchers, supercomputing effort reveal antibody secrets ...

ORNL teams with Los Alamos and EPB to demonstrate next-generation grid security tech ...

The Cloud

IBM Watson now available anywhere ...