We investigate strontium titanate as a model waste form for 90Sr. Implantation with O+ and Zr+ ions, followed by annealing at 1423 K, was performed to simulate 90Sr to 90Zr decays. At low Zr concentrations, we observe formation of a ZrO-Sr superlattice structure. Ab initio calculations indicate that this atomic configuration is energetically favorable. At higher Zr concentrations, we observe precipitates of ZrO2 with a coherently strained interface, or a monolayer of disordered interfacial structure. Potential candidacy of 90SrTiO3 as a waste form for permanent disposal of 90Sr is discussed.
Revised: July 25, 2020 |
Published: July 13, 2012
Citation
Jiang W., R.M. Van Ginhoven, L. Kovarik, J.E. Jaffe, and B.W. Arey. 2012.Superlattice Structure and Precipitates in O+ and Zr+ Ion Coimplanted SrTiO3: a Model Waste Form for 90Sr.Journal of Physical Chemistry C 116, no. 31:16709-16715.PNNL-SA-85385.doi:10.1021/jp301343b