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Title: Thermodynamic and structural evolution of mechanically milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore

Abstract

Design and synthesis of thermodynamically metastable yet kinetically achievable materials possessing various desired functional and physical properties have recently drawn tremendous scientific-attention. In addition to conventional heat treatments and wet chemistry approaches, energy deposition into materials can induce unique nonequilibrium phases with distinct structures, chemistry, energetics, and properties. Mechanochemical synthesis and ion beam irradiation are two processing techniques that provide access to phases and states far from equilibrium. By a combination of high temperature oxide melt solution calorimetry, differential scanning calorimetry (DSC), neutron pair distribution function (PDF) analysis, and supplementary powder X-ray diffraction (XRD), the energetics and multiscale structural evolution on annealing of ball milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore were investigated. Despite very similar structural modifications of local atomic arrangements and only minor differences in the long range structure, both types of damage yield significant difference in the energetics of the produced material. Here, the energy of destabilization in the milled sample (70.2 ± 8.2 kJ/mol) is much less endothermic than that in the irradiated sample (457.3 ± 8.0 kJ/mol). The DSC profiles, supported by neutron scattering, X-ray diffraction, and solution calorimetry, reveal decoupled annealing events in different temperature ranges, separating crystallization of long range pyrochlore structuremore » from annealing of short range weberite-like domains.« less

Authors:
 [1];  [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [5];  [2]; ORCiD logo [6]
  1. Univ. of California, Davis, CA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of Tennessee, Knoxville, TN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Cinvestav Unidad Saltillo, Coahuila (Mexico)
  5. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  6. Univ. of California, Davis, CA (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1569620
Alternate Identifier(s):
OSTI ID: 1570479
Report Number(s):
LA-UR-19-24244
Journal ID: ISSN 1359-6454; TRN: US2001066
Grant/Contract Number:  
89233218CNA000001
Resource Type:
Accepted Manuscript
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 181; Journal Issue: C; Journal ID: ISSN 1359-6454
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Pyrochlore; Irradiation effect; Ball milling; Amorphization; Annealing

Citation Formats

Chung, Cheng-Kai, O'Quinn, Eric C., Neuefeind, Joerg C., Fuentes, Antonio F., Xu, Hongwu, Lang, Maik, and Navrotsky, Alexandra. Thermodynamic and structural evolution of mechanically milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore. United States: N. p., 2019. Web. doi:10.1016/j.actamat.2019.09.022.
Chung, Cheng-Kai, O'Quinn, Eric C., Neuefeind, Joerg C., Fuentes, Antonio F., Xu, Hongwu, Lang, Maik, & Navrotsky, Alexandra. Thermodynamic and structural evolution of mechanically milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore. United States. doi:https://doi.org/10.1016/j.actamat.2019.09.022
Chung, Cheng-Kai, O'Quinn, Eric C., Neuefeind, Joerg C., Fuentes, Antonio F., Xu, Hongwu, Lang, Maik, and Navrotsky, Alexandra. Fri . "Thermodynamic and structural evolution of mechanically milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore". United States. doi:https://doi.org/10.1016/j.actamat.2019.09.022. https://www.osti.gov/servlets/purl/1569620.
@article{osti_1569620,
title = {Thermodynamic and structural evolution of mechanically milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore},
author = {Chung, Cheng-Kai and O'Quinn, Eric C. and Neuefeind, Joerg C. and Fuentes, Antonio F. and Xu, Hongwu and Lang, Maik and Navrotsky, Alexandra},
abstractNote = {Design and synthesis of thermodynamically metastable yet kinetically achievable materials possessing various desired functional and physical properties have recently drawn tremendous scientific-attention. In addition to conventional heat treatments and wet chemistry approaches, energy deposition into materials can induce unique nonequilibrium phases with distinct structures, chemistry, energetics, and properties. Mechanochemical synthesis and ion beam irradiation are two processing techniques that provide access to phases and states far from equilibrium. By a combination of high temperature oxide melt solution calorimetry, differential scanning calorimetry (DSC), neutron pair distribution function (PDF) analysis, and supplementary powder X-ray diffraction (XRD), the energetics and multiscale structural evolution on annealing of ball milled and swift heavy ion irradiated Er2Ti2O7 pyrochlore were investigated. Despite very similar structural modifications of local atomic arrangements and only minor differences in the long range structure, both types of damage yield significant difference in the energetics of the produced material. Here, the energy of destabilization in the milled sample (70.2 ± 8.2 kJ/mol) is much less endothermic than that in the irradiated sample (457.3 ± 8.0 kJ/mol). The DSC profiles, supported by neutron scattering, X-ray diffraction, and solution calorimetry, reveal decoupled annealing events in different temperature ranges, separating crystallization of long range pyrochlore structure from annealing of short range weberite-like domains.},
doi = {10.1016/j.actamat.2019.09.022},
journal = {Acta Materialia},
number = C,
volume = 181,
place = {United States},
year = {2019},
month = {9}
}