title: Laser-induced periodic surface structures nanofabricated on poly(trimethylene terephthalate) spin-coated films.
abstract: Here we present a precise morphological description of laser-induced periodic surface structures (LIPSS) nanofabricated on spin-coated poly(trimethylene terephthalate) (PTT) films by irradiation with 266 nm, 6 ns laser pulses and by using a broad range of fluences and number of pulses. By accomplishing real and reciprocal space measurements by means of atomic force microscopy and grazing incidence wide- and small-angle X-ray scattering respectively on LIPSS samples, the range of optimum structural order has been established. For a given fluence, an increase in the number of pulses tends to improve LIPSS in PTT. However, as the pulse doses increase above a certain limit, a distortion of the structures is observed and a droplet-like morphology appears. It is proposed that this effect could be related to a plausible decrease of the molecular weight of PTT due to laser-induced chain photo-oxidation by irradiation with a high number of pulses. A concurrent decrease in viscosity enables destabilization of LIPSS by the formation of droplets in a process similar to surface-limited dewetting.
authors.affiliation: Instituto de Estructura de la Materia, IEM-CSIC, IQFR-CSIC, Serrano 119-121, 28006 Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Martín-Fabiani
authors.forename: E
authors.initials: E
authors.lastname: Rebollar
authors.forename: S
authors.initials: S
authors.lastname: Pérez
authors.forename: D R
authors.initials: DR
authors.lastname: Rueda
authors.forename: M C
authors.initials: MC
authors.lastname: García-Gutiérrez
authors.forename: A
authors.initials: A
authors.lastname: Szymczyk
authors.forename: Z
authors.initials: Z
authors.lastname: Roslaniec
authors.forename: M
authors.initials: M
authors.lastname: Castillejo
authors.forename: T A
authors.initials: TA
authors.lastname: Ezquerra