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In pure oxygen at moderate temperatures of 200 °C, an fcc C60 transforms into amorphous carbon‐oxygen compounds and the icosahedral C60 molecular structure is destroyed. The maximum oxygen uptake of pure C60, O/C60, is 12. Isothermal TGA transformation curves are sigmoid‐shaped with the kinetic exponent n∼5/2 which conforms with a two‐dimensional nucleation and growth mode. The heat of formation for the carbon‐oxygen compounds is 90 kcal/mol O, and the formation energy for the reaction: 60C (graphite)→C60 molecule is estimated to be ∼600 kcal/mol.

Thermal sublimation of pure C60 and C70 has been used for depositing well‐characterized fullerene films on a variety of substrates. Film purity is determined by infrared absorption spectra and the extent of crystallinity of the face‐centered cubic structure by x rays. Thickness‐dependent optical and electrical measurements reveal uniform films over the thickness range 200–1000 A. We obtain optical absorption coefficients having values between those of Si and Ge and a relative permittivity having a value close to that of amorphous SiO2.

High-quality single-crystal Sc2O3 films a few nanometer thick have been grown epitaxially on Si (111) despite a huge lattice mismatch. The films were electron-beam evaporated from a Sc2O3 target. Structural and morphological studies were carried out by x-ray diffraction and reflectivity, atomic force microscopy, high-resolution transmission electron microscopy, and medium-energy ion scattering, with the initial epitaxial growth monitored by in situ reflection high-energy electron diffraction. The films have the cubic bixbyite phase with a remarkably uniform thickness and high structural perfection. The film surfaces are very smooth and the oxide/Si interfaces are atomically sharp with a low average roughness of 0.06nm. The films are well aligned with the Si substrate with an orientation relationship of Si(111)‖Sc2O3(111), and an in-plane expitaxy of Si[1¯10]‖Sc2O3[1¯01].

Superconducting Tl‐Ba‐Ca‐Cu‐O thin films 0.2–1.0 μm thick have been prepared on MgO(100) and SrTiO3(100) substrates by dc diode sputtering using a single oxide target. Films containing primarily the Tl2Ba2Ca1Cu2O8 phase were obtained with a Tc (R=0) at 102 K and a transport Jc of 104 A/cm2 at 90 K. For the nearly pure phase Tl2Ba2Ca2Cu3O10 films, the Tc’s (R=0) are higher at 116 K and the transport Jc’s at 100 K are of 105 A/cm2. Both types of films show a strong preferred orientation with the c axis perpendicular to the film plane. The rocking curve of the Tl2Ba2Ca2Cu3O10 films is 0.32° wide and the typical grain size is over 10 μm.

Highly oriented, epitaxial Y1Ba2Cu3O7−x thin films were prepared on MgO(100) by molecular beam epitaxy at a substrate temperature of 550–600 °C. The in situ growth was achieved by incorporating reactive oxygen species produced by a remote microwave plasma in a flow‐tube reactor. The epitaxial (001) orientation is demonstrated by x‐ray diffraction and ion channeling. In situ reflection high‐energy electron diffraction showed that a layer‐by‐layer growth has produced a well‐ordered, atomically smooth surface in the as‐grown tetragonal phase of an oxygen stoichiometry of 6.2–6.3. A 500 °C anneal in 1 atm of O2 converted the oxygen content to 6.7 to 6.8. Typical superconducting transport properties of an Y1Ba2Cu3O7−x film 1000 A thick are ρ(300 K)=325 μΩ cm, ρ(300 K)/ρ(100 K)=2.4, Tc(onset)=92 K, and Tc(R=0)=82 K. The transport Jc at 75 K is 1×105 A/cm2, and increases to 1×106 A/cm2 at 70 K.

We report for the first time the growth of high quality films of metastable α‐Sn. The structural properties of the molecular beam epitaxy grown metastable α‐Sn are investigated by means of in situ reflection high‐energy electron diffraction (RHEED) analysis, scanning electron microscopy including electron channeling patterns, and high‐resolution x‐ray scattering techniques. Scanning electron microscopy reveals a growth morphology of smooth and uniform surfaces. RHEED patterns yield a highly streaked (2×1) surface reconstruction suggesting a layer‐by‐layer growth mechanism. Triple‐axis x‐ray diffractometry was employed to determine structural parameters and the strain distribution. In‐plane rocking scans of the (400) reflection indicate a half width of 3 arcsec for the heterostructure α‐Sn/InSb. Out‐of‐plane scans reveal a tetragonal distortion perpendicular to the film plane, contributing a net strain of ∼0.28%. These results are in quantitative agreement with values calculated using simple elastic theory.