1. Philips Research Laboratories Eindhoven, High Tech Campus 11, 5656AE Eindhoven, The Netherlands, Nederlands Institute for Material Research (NIMR), 2628CD Delft, The Netherlands, IMM, Solid State Chemistry, Radboud University Nijmegen, Toernooiveld 1, 6525ED Nijmegen, The Netherlands, and FEI Company, Achtseweg Noord 5, Building AAE, 5600 KA Eindhoven/Acht, The Netherlands