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Title: X-ray diffraction and spectroscopy study of nano-Eu 2O 3 structural transformation under high pressure

Abstract

Nanoscale materials exhibit properties that are quite distinct from those of bulk materials because of their size restricted nature. Here, we investigated the high-pressure structural stability of cubic (C-type) nano-Eu2O3 using in situ synchrotron X-ray diffraction (XRD), Raman and luminescence spectroscopy, and impedance spectra techniques. Our high-pressure XRD experimental results revealed a pressure-induced structural phase transition in nano-Eu2O3 from the C-type phase (space group: Ia-3) to a hexagonal phase (A-type, space group: P-3m1). Our reported transition pressure (9.3 GPa) in nano-Eu2O3 is higher than that of the corresponding bulk-Eu2O3 (5.0 GPa), which is contrary to the preceding reported experimental result. After pressure release, the A-type phase of Eu2O3 transforms into a new monoclinic phase (B-type, space group: C2/m). Compared with bulk-Eu2O3, C-type and A-type nano-Eu2O3 exhibits a larger bulk modulus. Our Raman and luminescence findings and XRD data provide consistent evidence of a pressure-induced structural phase transition in nano-Eu2O3. To our knowledge, we have performed the first high-pressure impedance spectra investigation on nano-Eu2O3 to examine the effect of the structural phase transition on its transport properties. We propose that the resistance inflection exhibited at ~12 GPa results from the phase boundary between the C-type and A-type phases. Besides, we summarizedmore » and discussed the structural evolution process by the phase diagram of lanthanide sesquioxides (Ln2O3) under high pressure.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1342247
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Alloys and Compounds; Journal Volume: 701; Journal Issue: C
Country of Publication:
United States
Language:
ENGLISH
Subject:
36 MATERIALS SCIENCE; Rare earth sesquioxides; Nanocrystalline materials; High pressure; Structural phase transition

Citation Formats

Yu, Zhenhai, Wang, Qinglin, Ma, Yanzhang, and Wang, Lin. X-ray diffraction and spectroscopy study of nano-Eu2O3 structural transformation under high pressure. United States: N. p., 2017. Web. doi:10.1016/j.jallcom.2017.01.143.
Yu, Zhenhai, Wang, Qinglin, Ma, Yanzhang, & Wang, Lin. X-ray diffraction and spectroscopy study of nano-Eu2O3 structural transformation under high pressure. United States. doi:10.1016/j.jallcom.2017.01.143.
Yu, Zhenhai, Wang, Qinglin, Ma, Yanzhang, and Wang, Lin. Tue . "X-ray diffraction and spectroscopy study of nano-Eu2O3 structural transformation under high pressure". United States. doi:10.1016/j.jallcom.2017.01.143.
@article{osti_1342247,
title = {X-ray diffraction and spectroscopy study of nano-Eu2O3 structural transformation under high pressure},
author = {Yu, Zhenhai and Wang, Qinglin and Ma, Yanzhang and Wang, Lin},
abstractNote = {Nanoscale materials exhibit properties that are quite distinct from those of bulk materials because of their size restricted nature. Here, we investigated the high-pressure structural stability of cubic (C-type) nano-Eu2O3 using in situ synchrotron X-ray diffraction (XRD), Raman and luminescence spectroscopy, and impedance spectra techniques. Our high-pressure XRD experimental results revealed a pressure-induced structural phase transition in nano-Eu2O3 from the C-type phase (space group: Ia-3) to a hexagonal phase (A-type, space group: P-3m1). Our reported transition pressure (9.3 GPa) in nano-Eu2O3 is higher than that of the corresponding bulk-Eu2O3 (5.0 GPa), which is contrary to the preceding reported experimental result. After pressure release, the A-type phase of Eu2O3 transforms into a new monoclinic phase (B-type, space group: C2/m). Compared with bulk-Eu2O3, C-type and A-type nano-Eu2O3 exhibits a larger bulk modulus. Our Raman and luminescence findings and XRD data provide consistent evidence of a pressure-induced structural phase transition in nano-Eu2O3. To our knowledge, we have performed the first high-pressure impedance spectra investigation on nano-Eu2O3 to examine the effect of the structural phase transition on its transport properties. We propose that the resistance inflection exhibited at ~12 GPa results from the phase boundary between the C-type and A-type phases. Besides, we summarized and discussed the structural evolution process by the phase diagram of lanthanide sesquioxides (Ln2O3) under high pressure.},
doi = {10.1016/j.jallcom.2017.01.143},
journal = {Journal of Alloys and Compounds},
number = C,
volume = 701,
place = {United States},
year = {Tue Jan 17 00:00:00 EST 2017},
month = {Tue Jan 17 00:00:00 EST 2017}
}