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Title: Single crystal growth and structural evolution across the 1st order valence transition in (Pr 1–yY y) 1–xCa xCoO 3-δ

Here, praseodymium-containing cobalt perovskites, such as (Pr 1-yY y) 1-xCa xCoO 3-δ, have been argued to undergo a first-order charge shift between Pr and hybridized Co-O orbitals that leads to a metal-insulator transition at a temperature, T VT. Magnetization and x-ray absorption spectroscopy measurements on single crystals of (Pr 0.85Y 0.15) 0.7Ca 0.3CoO 3-δ grown in an IR image furnace under 40-60 bar of oxygen confirm the presence of this valence transition. Single crystal x-ray synchrotron diffraction measurements are consistent with an isomorphic phase transition at T VT. No evidence of charge ordering was revealed by the single crystal diffraction. Dissimilar to analytical transmission electron microscopy measurements performed on a grain from a polycrystalline sample that revealed an oxygen vacancy order-disorder transition at T VT, the present single-crystal measurements did not evidence such a transition, likely reflecting a lower density of oxygen vacancies in the high-pO 2 grown single crystals.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Univ. of Chicago, Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Published Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 254; Journal Issue: C; Journal ID: ISSN 0022-4596
Publisher:
Elsevier
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Materials Sciences and Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division; National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; perovskite; cobaltite; valence transition; insulator-metal transition; isomorphic transition
OSTI Identifier:
1368593
Alternate Identifier(s):
OSTI ID: 1373417

Schreiber, N. J., Zhang, Junjie, Zheng, Hong, Freeland, J. W., Chen, Yu -Sheng, Mitchell, J. F., and Phelan, D.. Single crystal growth and structural evolution across the 1st order valence transition in (Pr1–yYy)1–xCaxCoO3-δ. United States: N. p., Web. doi:10.1016/j.jssc.2017.06.026.
Schreiber, N. J., Zhang, Junjie, Zheng, Hong, Freeland, J. W., Chen, Yu -Sheng, Mitchell, J. F., & Phelan, D.. Single crystal growth and structural evolution across the 1st order valence transition in (Pr1–yYy)1–xCaxCoO3-δ. United States. doi:10.1016/j.jssc.2017.06.026.
Schreiber, N. J., Zhang, Junjie, Zheng, Hong, Freeland, J. W., Chen, Yu -Sheng, Mitchell, J. F., and Phelan, D.. 2017. "Single crystal growth and structural evolution across the 1st order valence transition in (Pr1–yYy)1–xCaxCoO3-δ". United States. doi:10.1016/j.jssc.2017.06.026.
@article{osti_1368593,
title = {Single crystal growth and structural evolution across the 1st order valence transition in (Pr1–yYy)1–xCaxCoO3-δ},
author = {Schreiber, N. J. and Zhang, Junjie and Zheng, Hong and Freeland, J. W. and Chen, Yu -Sheng and Mitchell, J. F. and Phelan, D.},
abstractNote = {Here, praseodymium-containing cobalt perovskites, such as (Pr1-yYy)1-xCaxCoO3-δ, have been argued to undergo a first-order charge shift between Pr and hybridized Co-O orbitals that leads to a metal-insulator transition at a temperature, TVT. Magnetization and x-ray absorption spectroscopy measurements on single crystals of (Pr0.85Y0.15)0.7Ca0.3CoO3-δ grown in an IR image furnace under 40-60 bar of oxygen confirm the presence of this valence transition. Single crystal x-ray synchrotron diffraction measurements are consistent with an isomorphic phase transition at TVT. No evidence of charge ordering was revealed by the single crystal diffraction. Dissimilar to analytical transmission electron microscopy measurements performed on a grain from a polycrystalline sample that revealed an oxygen vacancy order-disorder transition at TVT, the present single-crystal measurements did not evidence such a transition, likely reflecting a lower density of oxygen vacancies in the high-pO2 grown single crystals.},
doi = {10.1016/j.jssc.2017.06.026},
journal = {Journal of Solid State Chemistry},
number = C,
volume = 254,
place = {United States},
year = {2017},
month = {6}
}