Chemical effects in C-60 irradiation of polymers

The C-60 erosion behaviour of poly(methyl)methacrylate (PMMA), poly(alpha-methyl) styrene (PAMS) and polystyrene (PS) has been studied at various temperatures and compared with that under Ga+ irradiation. Strong variations of erosion yields are observed, indicating that chemical degradation mechanisms are operating. In particular, our results suggest that fast depolymerization mechanisms are important in leaving the surface of the sputter crater virtually undamaged. Since such mechanisms are connected with the chemical nature of the polymer, the possibility of performing molecular depth profiling of polymers with C-60 appears to depend strongly on the chemical nature of the system under study.