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Title: Radiation-induced disorder in compressed lanthanide zirconates

For this study, the effects of swift heavy ion irradiation-induced disordering on the behavior of lanthanide zirconate compounds (Ln 2Zr 2O 7 where Ln = Sm, Er, or Nd) at high pressures are investigated. After irradiation with 2.2 GeV 197Au ions, the initial ordered pyrochlore structure (Fm$$\bar{3}$$m) transformed to a defect-fluorite structure (Fm$$\bar{3}$$m) in Sm 2Zr 2O 7 and Nd 2Zr 2O 7. For irradiated Er 2Zr 2O 7, which has a defect-fluorite structure, ion irradiation induces local disordering by introducing Frenkel defects despite retention of the initial structure. When subjected to high pressures (>29 GPa) in the absence of irradiation, all of these compounds transform to a cotunnite-like ( Pnma) phase, followed by sluggish amorphization with further compression. However, if these compounds are irradiated prior to compression, the high pressure cotunnite-like phase is not formed. Rather, they transform directly from their post-irradiation defect-fluorite structure to an amorphous structure upon compression (>25 GPa). Defects and disordering induced by swift heavy ion irradiation alter the transformation pathways by raising the energetic barriers for the transformation to the high pressure cotunnite-like phase, rendering it inaccessible. As a result, the high pressure stability field of the amorphous phase is expanded to lower pressures when irradiation is coupled with compression. The responses of materials in the lanthanide zirconate system to irradiation and compression, both individually and in tandem, are strongly influenced by the specific lanthanide composition, which governs the defect energetics at extreme conditions.
ORCiD logo [1] ;  [1] ;  [2] ; ORCiD logo [3] ; ORCiD logo [4] ;  [5] ;  [6] ;  [7] ;  [1]
  1. Stanford Univ., CA (United States). Dept. of Geological Sciences
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
  3. Carnegie Inst. of Washington, Argonne, IL (United States). Geophysical Lab., High Pressure Collaborative Access Team (HPCAT)
  4. GSI-Helmholtz Centre for Heavy Ion Research, Darmstadt (Germany); Technical Univ. of Darmstadt (Germany)
  5. Univ. of Chicago, IL (United States). Center for Advanced Radiation Sources (CARS)
  6. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering
  7. Stanford Univ., CA (United States). Dept. of Geological Sciences; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; NA0001974; FG02-99ER45775; SC0001089; AC02-06CH1135; FC03-03NA00144
Accepted Manuscript
Journal Name:
Physical Chemistry Chemical Physics. PCCP (Print)
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics. PCCP (Print); Journal Volume: 20; Journal Issue: 9; Journal ID: ISSN 1463-9076
Royal Society of Chemistry
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division; Univ. of Notre Dame, IN (United States). EFRC Materials Science of Actinides (MSA); National Science Foundation (NSF); Carnegie Inst. of Science, Washington, DC (United States). Carnegie/DOE Alliance Center (CDAC)
Country of Publication:
United States
OSTI Identifier: