STRUCTURAL CHARACTERIZATION OF THE TEMPERATURE-DEPENDENCE OF C-60-THIN FILMS ON MICA(001) BY X-RAY-DIFFRACTION

Thin C-60 films have been deposited on mica(001) substrates by thermal evaporation at substrate temperatures between room temperature and 20 0 degrees C and at a constant deposition rate. The influence of the su bstrate temperature on the growth of C-60-thin films has been systemat ically investigated by x-ray diffraction. theta-2 theta measurements o f the (111) peaks show a decrease of the full width at half-maximum (F WHM) with increasing substrate temperature, leading to a minimum FWHM of 0.15 degrees for a substrate temperature of 200 degrees C. Oriented films with an out-of-plane mosaic spread of Delta omega=0.2 degrees c ould be grown at a substrate temperature of 150+/-25 degrees C. It can be shown that the in-plane epitaxial arrangement C-60(111)parallel to mica(001) is determined by the seeding conditions and is independent of the substrate temperature. An increasing substrate temperature enha nces the epitaxial alignment of the C-60 crystals oriented with a {111 } face parallel to surface and also the azimuthal alignment of the twi ns which are rotated by 60 degrees about the surface normal.