Viktoria V. Ivanovskaya,1,2,* Alberto Zobelli,1,3 Alexandre Gloter,1 Nathalie Brun,1 Virginie Serin,4 and Christian Colliex1 1Laboratoire de Physique des Solides, Université Paris-Sud, CNRS-UMR 8502, 91405 Orsay, France 2Institute of Solid State Chemistry, Ural Division of Russian Academy of Science, 620041 Ekaterinburg, Russia 3Laboratoire des Solides Irradiés UMR 7642, CNRS-CEA/DSM, École Polytechnique, F-91128 Palaiseau, France 4CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347, Toulouse Cedex 4, France Received 7 June 2008; revised manuscript received 2 September 2008; published 8 October 2008