1. College of Business, Technology and Engineering, Sheffield Hallam University, UK
2. Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza and CIBER-BBN, Spain
3. Department of Physics, University of York, UK
4. Materials Science Institute of Madrid (ICMM/CSIC), Spain
5. nanoTherics Ltd, Brookside Farm, Dig Lane, Warrington, WA2 0SH, UK
6. Applied Physics Department, Universidade de Santiago de Compostela, Spain
7. Instituto de Materiais (iMATUS), Universidade de Santiago de Compostela, Spain