Dorothy Hodgkin looked at how atoms fit together into very complicated molecules. She used X-ray crystallography to find out what penicillin and insulin look like. Knowing what the molecules look like has helped other scientists understand how these molecules work, and to make new medicines.
Dorothy Hodgkin used x-ray crystallography to unlock the crystal structure of complex molecules. Dr Olga Degtyareva, working at the University of Edinburgh, studies how the crystal structure of elements changes when they are subjected to very high pressures.
Can you briefly describe your research?
I study what happens to the crystal structure of materials when they are subjected to high pressures and temperatures. These extreme conditions are comparable to the conditions we find deep inside the earth.
Large pressures can be generated by focusing a lot of force onto a small area: imagine an elephant wearing a high-heeled shoe!
This principle is used in a device called a diamond anvil cell (image below, left) that generates very high pressures of up to one million atmospheres and above. And it fits in the palm of your hand. A tiny amount of a material is squeezed between the tips of two diamonds (image below, middle). Pressure causes extraordinary changes in properties. For example, oxygen, a familiar gas, solidifies on compression and at pressures of 170,000 times atmospheric pressure turns into a beautiful red crystal (image below, right).
(left) Diamond anvil cell; (middle) two opposed diamonds (~1.5 mm) squeeze the sample held in place by a piece of metal; (right) crystal of solid red oxygen (~30µm), encased in helium, captured on camera through a microscope, credit Serge Desgreniers.
Since diamonds are invisible to x-rays, we can shine the x-rays through the diamonds and record how the x-rays are scattered by the sample. We do this using a large central facility called a synchrotron - find out more at: http://www.diamond.ac.uk/. This gives us information about the positions of the atoms in the sample and with the help of computer programmes we can work out the crystal structure. My studies on the high-pressure behaviour of sulphur revealed a sequence of various ring and spiral chain structures (see the image below).
Due to diamonds being transparent, we can check how the sample looks like with the help of a microscope at any time during the experiment.
We use powerful lasers for the preparation of the experiments as well as for measurements of the sample's properties - you can see lasers being used in the video below. This video shows my colleagues in one of the labs in our centre.
These fundamental studies can potentially yield practical applications as they can help us make novel materials with valuable properties. At high pressures and temperatures, carbon in the form of graphite turns into diamonds! Big presses such as one in our centre can be used to make diamonds as well as other new materials: have a look at the press in this short film here, which was made by some of my colleagues.
Who inspired you to become a scientist?
I must have received some of my scientific inspiration as a baby
- as a child I was surrounded by crystallography books and models
of crystal structures, because my mother has been a scientist and a
high-pressure crystallographer for 40 years now. She supported many
of my interests throughout my childhood and my teenage years, such
as competing in tennis and mountain skiing, but I was also
influenced by a couple of excellent teachers during the last two
years of the school, and decided that I wanted to spend my working
life studying physics.
In the image above, my mother Valentina Degtyareva and my first son Thomas (at 4 months old), in Oxford University Museum of Natural History in 2007.
What subjects did you study at school and what did you do your degree in?
In the last two years of school, which I spent in my home town (a scientific centre near Moscow) right after the Soviet Union broke up, I studied a lot of maths and physics. I did my degree in physics, spending three years at the Moscow Lomonosov State University, and then three further years at the Paderborn University in Germany, where I did my Masters degree in the laboratory of Professor Holzapfel, a renowned high-pressure scientist.
What do you love about your job?
Working as a crystallographer gives me the opportunity to be creative and combine artistic and scientific thinking. It also feels good to be doing something that contributes to scientific understanding within the area in which I work. Any day can potentially bring a new discovery. I also love to play with diamonds, ruby, gold, and platinum on an everyday basis - these are all things that we use to conduct our research!
What are your hobbies?
My present hobbies are blogging about productivity at our work place and whatever interests my two sons (3.5 and 2 years old). This usually includes playing on the beach or in the forest discovering creatures that live there, or watching big machines at work, like tractors! Like most scientists, I get to travel a lot (to do experiments in other labs, and to conferences), and so I enjoy exploring new cities or nature reserves.
In the picture, the budding explorers, Olga's sons, on the Gullane beach near Edinburgh, have interrupted their sand play to observe something that captured their attention.
If you could go back in time and meet Dorothy Hodgkin, what would you like to ask her?
"How did it feel when you finally knew the answer to the big question of what the crystal structure of insulin is?"