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Title: Inelastic neutron scattering study on the electronic transition in ( Pr 1 - y Y y ) 1 - x Ca x CoO 3 single crystals

Abstract

The perovskite Co oxides $${\mathrm{Pr}}_{1{-}x}{\mathrm{Ca}}_{x}{\mathrm{CoO}}_{3}$$ exhibit at around $$x{\sim}0.5$$ an unusual transition at temperature $${T}_{\mathrm{S}}$$ [S. Tsubouchi et al. Phys. Rev. B 66, 052418 (2002)] with no space group change and no long-range magnetic order. We measured inelastic neutron scattering intensities of magnetic excitations $$I({Q},{\omega}$$) for two single crystals of ($${\mathrm{Pr}}_{1{-}y}{\mathrm{Y}}_{y}{)}_{1{-}x}{\mathrm{Ca}}_{x}{\mathrm{CoO}}_{3}$$ in which the $x$ region of the transition is widened by the Pr-site doping to study whether the recent proposal of the excitonic condensation model is relevant to this "hidden order transition" of the system. While $${{\chi}}^{{'}{'}}({Q},{\omega})$$ seems to have characteristics of strongly correlated Co $3d$ electrons above $${T}_{\mathrm{S}}$$, it abruptly exhibits a weak feature reminiscent of a pseudogaplike structure at $${T}_{\mathrm{S}}$$ with decreasing $T$. The first peak of the Pr crystal-field excitations has also been observed at low temperatures. Using a model of the coexistence of the exciton condensed phase (EC phase) with the nearly or weakly ferromagnetic one, we show that the EC phase appears as the collective transition in $${\mathrm{Pr}}_{1{-}x}{\mathrm{Ca}}_{x}{\mathrm{CoO}}_{3}$$.

Authors:
 [1];  [1];  [2];  [3]
  1. Comprehensive Research Organization for Science and Society, Tokai (Japan). Neutron Science and Technology Center
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
  3. Nagoya Univ. (Japan). Graduate School of Science
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Comprehensive Research Organization for Science and Society, Tokai (Japan); Nagoya Univ. (Japan)
Sponsoring Org.:
USDOE Office of Science (SC); Japan Society for the Promotion of Science (JSPS)
OSTI Identifier:
1481688
Alternate Identifier(s):
OSTI ID: 1480894
Grant/Contract Number:  
AC05-00OR22725; JP17K05558
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 20; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; excitons; quasiparticles; inelastic neutron scattering

Citation Formats

Moyoshi, Taketo, Kamazawa, Kazuya, Matsuda, Masaaki, and Sato, Masatoshi. Inelastic neutron scattering study on the electronic transition in ( Pr1-yYy)1-xCaxCoO3 single crystals. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.205105.
Moyoshi, Taketo, Kamazawa, Kazuya, Matsuda, Masaaki, & Sato, Masatoshi. Inelastic neutron scattering study on the electronic transition in ( Pr1-yYy)1-xCaxCoO3 single crystals. United States. doi:10.1103/PhysRevB.98.205105.
Moyoshi, Taketo, Kamazawa, Kazuya, Matsuda, Masaaki, and Sato, Masatoshi. Mon . "Inelastic neutron scattering study on the electronic transition in ( Pr1-yYy)1-xCaxCoO3 single crystals". United States. doi:10.1103/PhysRevB.98.205105.
@article{osti_1481688,
title = {Inelastic neutron scattering study on the electronic transition in ( Pr1-yYy)1-xCaxCoO3 single crystals},
author = {Moyoshi, Taketo and Kamazawa, Kazuya and Matsuda, Masaaki and Sato, Masatoshi},
abstractNote = {The perovskite Co oxides ${\mathrm{Pr}}_{1{-}x}{\mathrm{Ca}}_{x}{\mathrm{CoO}}_{3}$ exhibit at around $x{\sim}0.5$ an unusual transition at temperature ${T}_{\mathrm{S}}$ [S. Tsubouchi et al. Phys. Rev. B 66, 052418 (2002)] with no space group change and no long-range magnetic order. We measured inelastic neutron scattering intensities of magnetic excitations $I({Q},{\omega}$) for two single crystals of (${\mathrm{Pr}}_{1{-}y}{\mathrm{Y}}_{y}{)}_{1{-}x}{\mathrm{Ca}}_{x}{\mathrm{CoO}}_{3}$ in which the $x$ region of the transition is widened by the Pr-site doping to study whether the recent proposal of the excitonic condensation model is relevant to this "hidden order transition" of the system. While ${{\chi}}^{{'}{'}}({Q},{\omega})$ seems to have characteristics of strongly correlated Co $3d$ electrons above ${T}_{\mathrm{S}}$, it abruptly exhibits a weak feature reminiscent of a pseudogaplike structure at ${T}_{\mathrm{S}}$ with decreasing $T$. The first peak of the Pr crystal-field excitations has also been observed at low temperatures. Using a model of the coexistence of the exciton condensed phase (EC phase) with the nearly or weakly ferromagnetic one, we show that the EC phase appears as the collective transition in ${\mathrm{Pr}}_{1{-}x}{\mathrm{Ca}}_{x}{\mathrm{CoO}}_{3}$.},
doi = {10.1103/PhysRevB.98.205105},
journal = {Physical Review B},
issn = {2469-9950},
number = 20,
volume = 98,
place = {United States},
year = {2018},
month = {11}
}

Journal Article:
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