I was trying to figure out what it could be, but that makes sense.
I used AFM a tiny bit in grad school(it actually would have been around 2013-2014 that I did it) but never considered it having this sort of resolution. I guess Bucky Balls would be relatively large in the grand scheme of things, although we were mostly looking surface shapes/dimensions in my research group and the sort of resolution we were getting was good enough. My research group had our own AFM-my advisor had bought it as part of his start-up money in the early 2000s, and it was showing its age then. Most people in my group who regularly did it used the newer/better ones in the material characterization facility(associated with ChemE/Material Science). I used the one in our group the few times I did AFM. We were imaging changes in my Pd MPC nanoparticles before and after hydrogen exposure-we could see it but didn't publish anything since it really was just image of Pd aggregating on H2 exposure, which was well characterized, and we couldn't see the loss of the much smaller ligands which is what we were hoping for. I tried SEM but couldn't really see it either. I finally was able to see it on TEM, but only ended up with a few images. We had one TEM on campus, run exclusively by a full time faculty member, and even though I knew him well and had a great relationship with him, TEM was enough in demand that he was very selective about what he would even take for imaging and it was $$$.
If I may be permitted a bit more rambling about the imaged molecule-back in graduate school the graduate students ran a program where we would invite preferably a Nobel Laureate, or if not a prominent chemist(over nearly 40 years we'd had 20+ Nobel Laureates and also liked to brag that we'd had we'd had either 3 or 4 people give talks who later went on to win a Nobel Prize. As a student organization(albeit a VERY well funded one both from department-sanctioned fundraising and a local corporate sponsor) we couldn't offer the huge honorariums many of these folks would normally get, but we'd dangle a carrot that no one else could realistically offer-we took them to the Kentucky Derby as part of their visit. Nobel Laureates talk to each other, they knew our invitation was the "real deal", and had many decline for the current year but ask to be considered in the future.
In any case, I didn't really want it, but was practically strong armed into being president of the student organization for 2 years. We were 2 for 2 for Nobel Laureates during my time as president. My real point, though is that one of the two years I was president, our invited speaker was Bob Curl. He is know for, along with Richard Smalley and Harold Kroto, first noticing, elucidating, and then publishing the C60 Buckyball structure. He was genuinely a fine gentleman and one of my roles as president was playing host for his visit. I picked him up from the airport, dropped him off, arranged the schedule, and drove him around/took him out to dinner/all the other duties in the time in-between. Even though there were normally other people involved, I got to spend probably more one-on-one time with him than anyone else(same thing happened the next year with Mary Chalfie, another fine gentleman).
During one of Bob's talks, he showed us a lot of the data that lead to discovering these. They'd actually first seen a strange anomoly on C13 NMR-a single peak on a compound with a known molecular weight of 702. I think they confirmed the structure by XRD, which is the go-to method for that sort of stuff, but it was really interesting to see and hear(and NMR was nowhere near as good then as it is now, so the original single peak C13 NMR he showed us was...ugly...to say the least).
