GROWTH OF LARGE FULLERENE C-60 CRYSTALS AND HIGHLY ORIENTED THIN-FILMS BY PHYSICAL VAPOR TRANSPORT

We have grown C-60 Single crystals and thin films using physical vapor transport techniques. It took about 3-4 weeks to grow C-60 crystals w ith a dimension of up to about 8 mm in a sealed vacuum quartz tube. We have found that the growth proceeded by either the two-dimensional nu cleation or step flow mode depending on the orientation of crystal sur faces. In contrast, C-60 films grew much faster in an open quartz tube under vacuum. X-ray diffraction has revealed that these C-60 films ar e highly oriented in either (111)/(cover-glass substrate) or (220)/(fu sed silica substrate) orientations. Our explanation for this phenomeno n is that the orientation of C-60 crystals in their early growth stage can be adjusted by the rotation of the individual C-60 molecules at e levated temperatures.