1. Material Physics, School of Engineering Sciences, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
2. Alba Synchrotron Light Source, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, Barcelona, Spain
3. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States