The typical order of collaboration between theorists and experimental researchers is that theory comes first. The theoretician calculates a combination of substances and conditions that should give promising results. Then the experimental researcher tries to create the material in a lab. But for material researchers Florian Trybel and Dominique Laniel, this order is reversed.
“The experiments, which are currently very expensive, will probably not become much more effective or cheaper than they are now. Therefore, we need to keep up through our calculations and models to save time and resources,” says Florian Trybel, assistant professor at Linköping University.
He is a theorist in materials physics, working at the Division of Theoretical Physics. This involves him breaking down experimental observations into theoretical explanatory models, mainly focusing on what high pressure does to the laws of nature. There is a lack of knowledge that is required to be able to predict, with precision, what kind of materials can be created under extreme pressures and temperatures.
Just as nature creates diamond – ordinary carbon atoms exposed to extreme pressure – Florian Trybel and Dominique Laniel want to create new materials from other basic atoms that may have new and unexpected properties.
“We don’t know enough about what extreme environments do to the chemistry between substances in order to theoretically predict results with sufficient certainty. Before we’ve been able to analyse enough material, we’re often forced to test and see what happens,” says Florian Trybel,
Both researchers have received major financial contributions to develop the production of new materials in extreme environments and to build the fundamental mathematical models needed. It is a major undertaking and a necessity for scientists around the world to gain in-depth understanding of what extreme conditions, such as those involving high pressure and temperature, do to atoms and their bonds. In the long run, it may also provide an understanding of how we can use that knowledge to the benefit of humanity.
To create the new materials in the lab, Dominique Laniel uses a so-called diamond anvil. Put simply, a base material is placed between the tips of two diamonds, making an anvil that then exposes the material to pressure many millions of times higher than atmospheric pressure.
The temperature of the material in the anvil is then raised to many thousands of degrees Celsius with the help of a very powerful laser. If the experiment has been successful, a so-called synthesis takes place, where simple atoms and molecules combine to form intricate materials. The diamond anvil with the new material is then sent to a kind of particle accelerator called a synchrotron, which allows Dominique Laniel to determine the structure of the new material.
“Because of the high pressure, there is very little material we can create. This makes it extremely difficult to measure the properties of the new material. We therefore rely on Florian, who can use supercomputers for this,” he says.
The synchrotron shows how the atoms are arranged, that is to say, the material’s crystal structure. Once the crystal structure of the material is determined in the synchrotron, Florian Trybel analyses it using highly advanced calculations that require supercomputing power.
“If the chemical bonds between the atoms hold the material together, we have something to work with,” says Florian Trybel.
Once enough new materials have been created and analysed in this way, there will hopefully be enough data – a theoretical base – to create new mathematical models for materials produced under extreme conditions. This means that researchers in the future would not have to do as many experiments as now, which would streamline the research process.
Experiments in extreme environments have become possible thanks to the technological advances of recent years. This opens up a vast and unexplored world of complex materials with unexpected chemical properties.
By breaking with the normal way of working and instead moving from experiment to theory, Florian Trybel and Dominique Laniel can explore the materials world and use what they call chemical intuition to decide which combinations to test.
“Together, Florian and I have experience and knowledge that give us some intuition about what we can test to produce interesting materials,” says Dominique Laniel.
“The dream scenario for me is for us to be able to find ways to create these materials under lower pressure, so that they can be mass produced and benefit humanity,” says Dominique Laniel.
For that to be possible, research must first increase the understanding of why high pressure affects the chemistry between substances in the way it does. According to Florian Trybel, more pieces of the theoretical puzzle need to be put in place.
“For us theorists, the goal is to be able to say what’s needed in an experiment to get a certain crystal structure, so we have to understand why the structures are as they are and continue to collaborate with our experimental colleagues.”
