Using crystallography to open the gates to the Earth’s interior

The Royal Swedish Academy of Sciences has decided to award the Gregori Aminoff Prize in Crystallography 2017 to Professor Natalia Dubrovinskaia and Professor Leonid Dubrovinsky of University of Bayreuth, Germany “for having developed new methodology for in situ-experimental determination of crystal structures subjected to extreme conditions of high temperature and pressure”. The prize amount is a total of 100,000 Swedish krona.

Very early on in the field of Geology, phase transitions in the Earth’s interior were invoked as an explanation of processes that are observed at the surface, such as continental drift, heat flows and earthquakes. Experimental methods were developed in order to study the deep rock that is not available for direct observation. In the 1970s diamond anvil cells (DAC) were devised, and today they constitute an important tool in the study of crystals subjected to pressures comparable to the high pressure levels found in the Earth’s mantle down to a depth of 3,000 kilometres.

High temperatures in pressure cells, thousands of degrees, are obtained by focusing laser beams into the DAC. Leonid Dubrovinsky’s contribution in this respect has been considerable.

Crystallography is the study of atomic structures in solids in order to determine, with high precision, where the atoms are located inside a molecule. Crystallography is used in chemistry, biology, medicine, geology and the material sciences.

The Laureates, spouses Professor Dubrovinsky and Professor Dubrovinskaia, share a background in mineralogy and crystallography and began their experiments in the middle of the 1990s, studying oxides, silicates and (MgFe)-silicates of relevance to the Earth’s geochemistry. Experimental results are analysed in situ using X-ray techniques, leveraging synchrotron light sources in order to increase the intensity of the extremely small sample located in the diamond cell. The transformation and structure of the mineral can then be determined with reference to the experimental pressure and temperature conditions.

A consequence of high pressure structural transformation is that the crystals’ physical properties, such as hardness, conductivity, magnetism and superconductivity, are altered.

Dubrovinsky and Dubrovinskaia have developed methods for carrying out physical experiments in DACs that have paved the way for technical applications in the material sciences. We can now manufacture artificial materials as hard as diamonds.

“The Laureates have made substantial contributions to developing techniques for observation of single crystals. They have created a high-quality application that enables the examination of minerals deep down in the Earth’s interior that could not otherwise have been studied” says Hans Annersten, member of the Prize committee and Professor Emeritus of Mineral Chemistry and Petrology at Uppsala University.

The Laureates are currently active at the University of Bayreuth, Germany. In the 1990s, the couple lived in Sweden for a while, having moved there in 1994 with their two young children, in order to carry out research at the Department of Earth Sciences at Uppsala University.

The Prize Ceremony will be held during the Royal Swedish Academy of Sciences’ annual celebration on 31 March 2017. In relation with the prize ceremony a scientific symposium will be organized on a topic relevant to the prize.

The Laureates

Natalia Dubrovinskaia, born 1961, PhD 1989 in the field of crystallography and crystal physics at Moscow State University. Since 2011 Professor of Crystallography and Crystal Physics, University of Bayreuth, Germany.

Leonid Dubrovinsky, born 1961, PhD 1986 in the field of mineralogy and crystallography at Moscow State University. Since 2009 Professor of High Pressure Crystallography at the Bavarian Research Institute of Experimental Geochemistry and Geophysics (BGI), University of Bayreuth, Germany.

The Royal Swedish Academy of Sciences, founded in 1739, is an independent organisation whose overall objective is to promote the sciences and strengthen their influence in society. The Academy takes special responsibility for the natural sciences and mathematics, but endeavours to promote the exchange of ideas between various disciplines.