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Title: Sculpting Nanoscale Functional Channels in Complex Oxides Using Energetic Ions and Electrons

The formation of metastable phases has attracted significant attention because of their unique properties and potential functionalities. In the present study, we demonstrate the phase conversion of energetic-ion-induced amorphous nanochannels/tracks into a metastable defect fluorite in A 2B 2O 7 structured complex oxides by electron irradiation. Through in situ electron irradiation experiments in a scanning transmission electron microscope, we observe electron-induced epitaxial crystallization of the amorphous nanochannels in Yb 2Ti 2O 7 into the defect fluorite. This energetic-electron-induced phase transformation is attributed to the coupled effect of ionization-induced electronic excitations and local heating, along with subthreshold elastic energy transfers. We also show the role of ionic radii of A-site cations (A = Yb, Gd, and Sm) and B-site cations (Ti and Zr) in facilitating the electron-beam-induced crystallization of the amorphous phase to the defect-fluorite structure. The formation of the defect-fluorite structure is eased by the decrease in the difference between ionic radii of A- and B-site cations in the lattice. Molecular dynamics simulations of thermal annealing of the amorphous phase nanochannels in A 2B 2O 7 draw parallels to the electron-irradiation-induced crystallization and confirm the role of ionic radii in lowering the barrier for crystallization. Furthermore, these results suggest thatmore » employing guided electron irradiation with atomic precision is a useful technique for selected area phase formation in nanoscale printed devices.« less
ORCiD logo [1] ; ORCiD logo [1] ;  [2] ;  [3] ; ORCiD logo [4] ; ORCiD logo [1] ; ORCiD logo [5]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Chinese Academy of Sciences, Shanghai (China)
  3. GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany); Technische Univ. Darmstadt, Darmstadt (Germany)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  5. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 10; Journal Issue: 19; Journal ID: ISSN 1944-8244
American Chemical Society (ACS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE; electron irradiation; in situ scanning transmission electron microscopy; Ion irradiation; molecular dynamics; phase transformation
OSTI Identifier: