1. Departamento de Física, FFCLRP, Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-900, Ribeirão Preto, Brazil
2. Electron Microscopy Facility, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen PSI, Switzerland
3. Department of Radiation Safety and Security, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen PSI, Switzerland