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. 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.
| Original language | English |
|---|---|
| Pages (from-to) | 309-317 |
| Number of pages | 9 |
| Journal | Acta Materialia |
| Volume | 181 |
| DOIs | |
| State | Published - Dec 2019 |
| Externally published | Yes |
Funding
This work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by the U.S. Department of Energy , Office of Science, Basic Energy Sciences under Award Number DE-SC0001089 . The last stage of this work was also supported by the Laboratory Directed Research and Development (LDRD) program (Project # 20180007 DR) of Los Alamos National Laboratory , and Thermodynamic Controls on the Synthesis, Structure and Reactivity of Materials for Energy, Department of Energy, Office of Science, Basic Energy Sciences under Award Number DE-FG02-03ER46053 . LANL, an affirmative action/equal opportunity employer, is managed by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract 89233218CNA000001 . E.C.O. acknowledges support from the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under contract number DE‐SC0014664 . A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Financial support from Mexican Conacyt to AFF's group (Grant CB2013-221701 ) is greartly appreciated. This work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award Number DE-SC0001089. The last stage of this work was also supported by the Laboratory Directed Research and Development (LDRD) program (Project # 20180007 DR) of Los Alamos National Laboratory, and Thermodynamic Controls on the Synthesis, Structure and Reactivity of Materials for Energy, Department of Energy, Office of Science, Basic Energy Sciences under Award Number DE-FG02-03ER46053. LANL, an affirmative action/equal opportunity employer, is managed by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract 89233218CNA000001. E.C.O. acknowledges support from the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under contract number DE?SC0014664. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Financial support from Mexican Conacyt to AFF's group (Grant CB2013-221701) is greartly appreciated.
| Funders | Funder number |
|---|---|
| AFF | |
| DOE Office of Science | |
| Energy Frontier Research Center | |
| Mexican Conacyt | CB2013-221701 |
| Office of Science Graduate Student Research | |
| SCGSR | |
| U.S. Department of Energy | DE-FG02-03ER46053, DE‐SC0014664 |
| Office of Science | |
| Basic Energy Sciences | DE-SC0001089 |
| National Nuclear Security Administration | 89233218CNA000001 |
| Workforce Development for Teachers and Scientists | |
| Oak Ridge National Laboratory | |
| Oak Ridge Institute for Science and Education | |
| Laboratory Directed Research and Development | 20180007 |
| Los Alamos National Laboratory |
Keywords
- Amorphization
- Annealing
- Ball milling
- Irradiation effect
- Pyrochlore