Large-area single-crystalline vanadium dioxide nanoflakes were first fabricated via a thermal reduction method in a tube furnace. The sample was characterized by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results show that VO2 nanoflakes are single-crystalline with a monoclinic structure. The VO2 nanoflakes have a width of 200–300 nm, a thickness of 50–100 nm, and a length up to 1–2 μm. It is found that single-crystalline VO2 nanoflakes show a novel and complicated 5–7-step Li-storage behavior for an insertion amount of <0.6 mol lithium per mol of VO2.

The frictional behaviors of fullerenes C60 and C70 were studied because they were speculated to be solid lubricants. For the sublimated pure C60 films on Si(001), a high friction coefficient (0.55–0.8) was observed under different loads and pin materials. For the C70 film, the friction coefficient showed a pin dependence, which changed from 0.5 with an Al2O3 pin to about 0.9 with a 440 stainless steel pin. The relatively high friction coefficients of C60 and C70 films were due to the tendency of the C60 and C70 particles to clump and compress into high shear strength layers rather than due to the impurities in the fullerenes. The benzene-solvated C60 · 4C6H6 and C70 ·xC6H6 showed a lowered friction coefficient (0.25 for C60 · 4C6H6 and 0.3 for C70 · xC6H6), which might result from the lowered shear strength of the hcp structure of C60 · 4C6H6 and C70 ·xC6H6 molecular crystals in which the benzene molecules were intercalated.