1 Erratum to: Appl. Phys. A (2015) 121:1235–1242 DOI 10.1007/s00339-015-9495-3

The original version of this article unfortunately contained a mistake.

The first and last names of the authors were interchanged. The correct names are Roberta Iannaccone, Susanna Bracci, Emma Cantisani, Barbara Mazzei.