title: Confinement effects of ion tracks in ultrathin polymer films.
abstract: We show direct experimental evidence that radiation effects produced by single MeV heavy ions on a polymer surface are weakened when the length of the ion track in the material is confined into layers of a few tens of nanometers. Deviation from the bulk (thick film) behavior of ion-induced craters starts at a critical thickness as large as ∼40  nm, due to suppression of long-range additive effects of excited atoms along the track. Good agreement was found between the experimental results, molecular dynamic simulations, and an analytical model.
authors.affiliation: Faculdade de Física, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga 6681, 90619-900 Porto Alegre, Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Papaléo
authors.affiliation: Faculdade de Física, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga 6681, 90619-900 Porto Alegre, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Thomaz
authors.affiliation: Faculdade de Física, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga 6681, 90619-900 Porto Alegre, Brazil.
authors.forename: L I
authors.initials: LI
authors.lastname: Gutierres
authors.affiliation: Campus Laranjeiras do Sul, Universidade Federal da Fronteira Sul, BR 158 km 405, 85301-970 Laranjeiras do Sul, Brazil.
authors.forename: V M
authors.initials: VM
authors.lastname: de Menezes
authors.affiliation: Materials Research, GSI Helmholtz Centre, Planckstrasse 1, 64291 Darmstadt, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Severin
authors.affiliation: Materials Research, GSI Helmholtz Centre, Planckstrasse 1, 64291 Darmstadt, Germany.|Technische Universität Darmstadt, Alarich-Weiss-Straße2, 64287 Darmstadt, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Trautmann
authors.affiliation: Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza 5500, Argentina.
authors.forename: D
authors.initials: D
authors.lastname: Tramontina
authors.affiliation: Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza 5500, Argentina.
authors.forename: E M
authors.initials: EM
authors.lastname: Bringa
authors.affiliation: Instituto de Física, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 9500, 91501-970 Porto Alegre, Brazil.
authors.forename: P L
authors.initials: PL
authors.lastname: Grande
mesh_terms: D020450:Heavy Ions; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D019904:Polymethyl Methacrylate / Q000737:chemistry*
chemical_list: D019904:Polymethyl Methacrylate