Awards > Awardee Interviews > Interview

Interview: Dr. Max Lagally

1991 Medard W. Welch Award Recipient

PHIL COHEN: I'm Phil Cohen from the University of Minnesota. The purpose of this today is to interview Professor Max Lagally from the University of Wisconsin, who is the 1991 Medard Welch Award recipient of the American Vacuum Society. Professor Lagally graduated from Penn State University in 1963 and he went on to University of Wisconsin to work with Barney Webb. There he did electron diffraction and sailed M20 sailboats. In 1968 he graduated in physics in Wisconsin and then went to the Fritz-Haber Institute in Berlin, Germany to do a fellowship for a year. He then came back to University of Wisconsin and joined the Material Science department in 1971, where he's now the Bascom Professor of Material Science. 
Today is November 12, 1991. This is the second day of the 28th National American Vacuum Society Symposium. It's appropriate that we ask Professor Lagally how he began in Physics and trace your career a bit and find out how you chose the problems you're working on today. How did you start in physics?

LAGALLY: Phil, thanks for being here to do this interview. I really got my start in physics relatively early compared to most people because I was fortunate enough to be a friend of the family of Erwin W. Mueller, who is the inventor of the field-ion microscope (FIM) and who is quite well known. In fact, he's the first Medard Welch awardee back in 1970, I would guess, or somewhere in that neighborhood. 

So he invited me to work with him in the laboratory when I was still a high school student. I did that, and for the first things I did was sweeping floors, working in a darkroom. One project I remember doing was painting cork balls on a cork ball model of a field emission tip. I'd paint them with fluorescent paint, then illuminate the whole image on the wall. It would light up and show just what the real FIM images were showing. 

It was very interesting working with Mueller because he was an excellent man in terms of technology in the lab, experimental methods. I learned a lot of just how to do things with my hands that were quite valuable later on. It sort of set me up, I believe, for looking at certainly condensed-matter physics and also looking at surfaces, because here we were seeing atoms really for among the first time ever. It set me up for also looking at disorder in surfaces because we saw individual planes, we saw screw dislocations and various things like that coming up. So it was quite a delightful way to start. Then of course in graduate school when I had a choice, I maintained the interest in surfaces and worked with Barney Webb, who was then one of the persons starting out in low-energy electron diffraction. That's how I got into that business.

COHEN: So you started out looking at real space images of surfaces, and then you switched to diffraction?

LAGALLY: That was tough [laughs].

COHEN: Then later you finally gave up and moved back into scanning tunneling microscope images in real space. 

LAGALLY: That's coming full circle, yes. I decided that looking at reciprocal space was really very comfortable and comforting, but when you saw the images in real space you could really believe it. I recommend it. It's a nice way to go. So we're back looking at actual positions of atoms in real space with STM, but I got my start looking at atoms in real space on the FIM. 

COHEN: We'll come back to STM in a bit. How did you start in the vacuum area? Do you recall your first talk?

LAGALLY: I recall my first meeting. It was the Palmer House in Chicago, actually. It was a very good meeting. At that time, the meetings were much smaller. 

COHEN: What was the focus of the meetings in those days?

LAGALLY: Of course, there were many fewer divisions. There was Surface Science, there was Vacuum Technology, Vacuum Metallurgy, I guess maybe it was called at the time. There were no Electronic Materials. There was no Plasma Science. There was a Thin Film Division at the time, I believe, already. The Surface Science Division was of course the youngest, the newest area and very dynamic. The Surface Science Division Post-Deadline session I remember as being very raucous and wild and people excited about the newest results. And drinking beer, of course. That was very important. We had really exciting times at these sessions all the time. 

What got me started in the Society also was one time Barney Webb was asked whether he would be part of the Surface Science Division Executive Committee. He said, no, he didn't want to do that; why don't they ask me. So I got a call from somebody (I forget who) that said, "Would you like to be on the Executive Committee in the Surface Science Division?" So I got into the organization in that way. I have not missed more than one Vacuum Society meeting in 20 years except 1987 when I was in Australia. It's been a very wonderful society for me. The AVS focus has always been the kinds of things I've been very interested in. 

COHEN: Part of your success has been finding bright people to work with and you established a group with a mix of post-docs and recruiting. How do you treat people? How do you find good students?

LAGALLY: I think the secret of success is to realize your own limitations and to hire people who are better than you. If you can do that, if you can hire people that are better than you and then let them work, then number one, you make for happy students, students who feel that they have a contribution to the whole project of their own. Rather than directing them, you let them choose. Of course, they go down wrong avenues and make mistakes and you have to help them through that. But fundamentally, I've been lucky to be able to surround myself with students who are fundamentally brighter and better than I am. 

In terms of using post-docs, I'm an experimentalist, and I've chosen to use theoretical post-docs in the things that I've done, because a lot of the diffraction work we have done, and now also the STM work, really has required a theoretical understanding that demanded an expert in that area. I've been lucky to find a person, frequently, that would be happy to interact with experimentalists at that level and contribute in that way. So we have had the very dynamic interaction between theorists and experimentalists simply because we've had them both in a group together. I think most of the people feel in the group that they're making real contributions, that the projects are their own rather than that I'm directing them.

COHEN: Besides directing and maintaining the right mix of students and post-docs, you've also chosen important problems. How did you choose problems? Give some advice to the rest of us here. 

LAGALLY: That's a good question. It's not easy to answer this question. In some sense, there's a certain feel to that. I think that it's perfectly clear that what I've been wanting to do is to find a problem that was a little bit out in front of where everyone was working. Now, how do you do that? I think that I try to integrate the knowledge that I gain from other people and say where should we be a couple years from now? I use input from the students who, I think—as I said a minute ago—are able to make contributions of their own that are valuable. On that basis, we have been able to stay. 

We've also chosen the field. The structural disorder field was something that no one really cared about when we started, as you know. You just knew from the development of X-ray diffraction of bulk disorder, bulk structures, that this would have to come sooner or later. So in some sense, for many years we were working in an area that no one cared about. It's caught up, and I think we just were lucky to have been there. So a lot of it's just serendipity. Some of it is just trying to be a little bit ahead and using what available brainpower is around you to try to do that. That's not a good answer, but I think that's in some way how we've accomplished it. 

COHEN: Let's be a bit more specific. One of the areas you've chosen to work with has been on silicon. Silicon has been around for ages. It's been studied and studied. Yet, you decided to go work on it more, and it made important contributions. How did you choose silicon?

LAGALLY: That really was serendipity. In retrospect it seems obvious. Silicon is a material that semiconductor technology is based on. But when we started to work in it, it was a time actually when funding agencies were not interested in funding the subject at all. We got into it in a way that was actually testing out our electron diffractometer resolution. Because I feel my contributions have been more in terms of developing techniques for measuring disorder than they have been in actual solving of particular problems, at least in the earlier years. In that sense, we were using silicon simply as a tool initially to test the instrument. Then we discovered interesting new aspects of it. 

Now, of course, it turns out that just by luck that silicon is one of the best surfaces for scanning tunneling microscopy on, and you can study a lot of the fundamental processes of crystal growth, which is what we're doing now, with pristine silicon as a model structure. It's just luck that it turned out to be very important. There's no particularly brilliant thinking involved in picking that. It's just luck. 

COHEN: Based upon your experiments on silicon and tungsten diffraction and imaging, what are the important problems the rest of us should be working on in the next few years?

LAGALLY: I think that if you look at where surface science has made its contributions in vacuum technology, it's clearly in the area initially of surface chemistry and surface reactions, but more recently in film growth and in aspects of kinetics of atomic transport processes. I think that if you look at where our technology is going, at least in the thin film area, it all is in metastable structures and multilayer composites and electronic materials combinations, layered structures. And all of those are going to require a good understanding of growth and of the structure and the disorder and the kinetic processes and equilibrium processes. My guess is that, in terms of my perspective of the kind of subject I know about, structure and morphology, we will have a long, rich future in this area in terms of studying the really fundamental aspects of crystal growth and applying those to more novel devices. And nanostructures, as we use the STM to fabricate or analyze ever smaller structures. There's a whole rich history of things that we can do that I think will be very valuable in that respect.

COHEN: Well, thank you very much.

LAGALLY: One thing in retrospect, one of the most important persons for me in the Vacuum Society was Len Beavis, who is of course one of the old members of the Society, a well known member. He was always very enthusiastic when I first came to the Society and he introduced me to everybody; he was eager to have people participate. He was one of the guiding lights that attracted me to the Society and kept me active in it. The Society has been very good to me, too, in terms of just the right kind of professionalism. And the mix of people that are here has been very valuable in furthering my own career and my own objectives. I think my students have gained a lot from coming to these meetings. It's been a very profitable - personally profitable and professionally profitable - Society to be participating in. Thanks for your time.