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Chemistry professor Mark Turnbull and his students create new compounds in order to study complex magnetic properties. Dr. Turnbull also sponsors students, like chemistry minor Lesley Mathews, who want to pursue internships in the local area. |
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Meet the researchers: Not having to choose
Interview with Brian Landry
Physics and chemistry double-major Brian Landry '05 has found a research project at Clark that will allow him to explore his interests in both disciplines. A Murdock Award for summer 2003 made it possible for him to work as a fulltime, paid researcher studying low dimensional magnets. Below is a summary of a recent conversation with him.
(Spring 2006 Update: Brian is now at Harvard University working toward a Ph.D. in the Department of Chemistry and Chemical Biology.)
Did you know that you wanted to study both chemistry and physics when you started at Clark?
Yes. Since high school I've been interested in the sciences. Chemistry and physics are my favorites. I wasn't able to choose between them, so I decided to do both.
Was this past summer the first time you participated in research at Clark?
No, I actually started working part-time on the project about halfway through the fall semester of my sophomore year. Then this past summer I was able to continue with it fulltime. I'm still involved with the same project now.
How did you get started in research?
I talked to my advisor, Dr. Thurlow, the beginning of my sophomore year and said I was interested in getting involved with research. It was something I'd always wanted to do. He suggested that I try Dr. Turnbull's lab. Dr. Turnbull is a chemist, and his lab works closely with that of Dr. Landee, who's a physicist. Since I'm both a chemistry and a physics major, that would give me the option of focusing on the research from the perspectives of both subjects. So it's a good situation.
How did you find out about the Murdock funding?
Dr. Turnbull suggested it; he said that if I wanted to continue my work over the summer I should apply. I thought that was a good idea, so I filled out the application and received the award. For the application process I had to write out a summary of my research: what I planned to do, and what I had done so far.
Were there other students working in the lab as well this past summer?
Yes. There were four other undergrads and two Ph.D. students.
Can you describe the project you were working on?
I was trying to synthesize--that is, create--a new compound in the form of a crystal that I hoped would have special magnetic properties. I wanted to create, first a structure called a chain, and then a ladder. A chain is a string of atoms arranged in linear formation. A ladder is made of two or more chains lined up side by side. The chains act as the ladder's "rails" and the "rungs" represent molecules joining the chains to each other. The metal atoms contained in the chains and ladders each have a magnetic moment.
What is a magnetic moment?
The tiny magnetic field that any electron generates. We want to study how the magnetic moments affect one another in various arrangements. In the ladder the magnetic moments can affect each other both vertically, along the rungs, and horizontally, along the rails. In a chain the magnetic moments interact in just one direction, along the "rail."
Crystals made of chains or ladders are examples of low dimensional magnets. A chain forms a one-dimensional structure, while a ladder is sort of between one and two dimensions. At some point, when enough chains get added to a ladder it will begin to act like a two dimensional magnet. But we don't know how many chains are necessary for that to happen.
Why do you want to create crystals, specifically?
Crystals allow us to use a technique called x-ray crystallography. X-rays are aimed at the crystal, and the resulting diffraction patterns help give us clues to the crystal's structure, in other words, whether its atoms are arranged in chains or ladders. If you have a structure that turns out to be a chain, then the magnetic data should graph as one type of curve, whereas the magnetic data of different type of structure would graph differently. I think I've maybe created a crystal that's never had its structure solved.
So the process is that you create a crystal, send it out for x-ray crystallography to try to get an indication of the structure, and then study the magnetic properties?
Yes, although you can study the magnetic properties without knowing the structure, but you don't learn as much.
So that means that when you first create the compound, you're not sure how the atoms will arrange themselves.
Right. What I do is mix two compounds in a solution, and try to grow crystals. I don't know what the resulting crystal structure will be.
Are you able to make educated guesses about what compounds might, in combination, make useful crystals for study?
Yes. Some compounds naturally act as ligands towards metals, that is, they have the potential to attach to the nickel and copper metal ions that we start with. When that combination takes place in a solution, there are usually several possible crystal structures that could result. Sometimes you might get two different types of crystals, each with a different structure, from the same solution.
Why does that happen?
How crystals form isn't understood that well, but different crystals might arise from slight variations in temperature or concentration within the solution. When a crystal forms, it pulls some of the compounds from the solution, thus changing the concentration of the solution. You might get one type of crystal first, and then another type later when the concentration is different.
That sounds really interesting--being able to invent new materials.
It is, and it's fun, too!
Can you comment on the advantages and disadvantages of participating in research while you're still an undergrad?
The big advantage for me is that when I'm doing research, I'm doing something new and current. That's really exciting. The only disadvantage is the time you have to put towards it. But if you have the time, and think it's worth it, which I do, then it's a good thing to do.
When you're working in the lab, do you interact with the other student researchers there, or do you pretty much just work on your own?
We definitely interact. We all have slightly different projects, but if someone has a question about something, others are there to help.
Are you hoping to do some physics research as well?
Yes. Right now I'm focusing more on the chemistry aspect-the synthesis of new crystals, but I hope later on to focus on the problem from a physics perspective. Both physicists and chemists can contribute to the study of magnetism.
For more information on low dimensional magnet research at Clark, visit Dr. Turnbull's Active Learning and Research pages.
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Additional Resources
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Brian Landry
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Something new and current