The Role of Antisite Disorder on Pre-Amorphization Swelling in Titanate Pyrochlores

Blas Uberuaga (1) , Yuhong Li (2) , Chao Jiang (3) , Samrat Choudhury (1) , James Valdez (1) , Maulik Patel (1) , Jonghan Won (1) , Yongqiang Wang (1) , Ming Tang (1) , Doug Safarik (1) , Darrin Dyler (1) , Ken Mcclellan (1) , Igor Usov (1) , Thomas Hartmann (4) , Gianguido Baldinozzi (5, 6) , Kurt Sickafus (1)

1 LANL - Los Alamos National Laboratory
2 School of Information science and engineering
3 Dept Engineering
4 Harry Reid Center for Environmental Studies
5 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides
6 LA2M - Laboratoire d'Analyse Microstructurale des Matériaux

Ion irradiation experiments and atomistic computer simulations were used to demonstrate that irradiation-induced lattice swelling in a complex oxide, Lu2Ti2O7, is due initially to the formation of cation antisite defects. X-ray diffraction (XRD) revealed that cation antisite formation correlates directly with pre-amorphization lattice swelling. XRD indicates that the volume per cation antisite pair is approximately 12 cubic angstroms. First principles calculations revealed that lattice swelling is best explained by near-neighbor antisite defects. Temperature accelerated dynamics simulations indicate that cation Frenkel defects are metastable and decay to form neighboring antisite defects.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Blas Uberuaga, Yuhong Li, Chao Jiang, Samrat Choudhury, James Valdez, et al.. The Role of Antisite Disorder on Pre-Amorphization Swelling in Titanate Pyrochlores. Symposium A : MRS Fall Meeting 2011, Nov 2011, Boston, United States. pp.A6.6. ⟨hal-00648294⟩