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Title: Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo{sub 4}O{sub 7.50}

Abstract

The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo{sub 4}O{sub 7}, using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo{sub 4}O{sub 7.50}, to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo{sub 4}O{sub 7}, is curiously similar to that of the members of the LnBaCo{sub 4}O{sub 7} series, in spite of its excess oxygen. Its magnetic study shows that this phase, like CaBaCo{sub 4}O{sub 7}, is ferrimagnetic with the same T{sub C} (60 K), but differently exhibits an unusual magnetic hysteresis. This exceptional behavior of CaBaCo{sub 4}O{sub 7} with respect to oxidation as well as the magnetic properties of CaBaCo{sub 4}O{sub 7.50} is interpreted in terms of the presence of defects due to oxidation. - Graphical Abstract: The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo{sub 4}O{sub 7}, using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo{sub 4}O{sub 7.50}, to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo{sub 4}O{sub 7}, is curiously similarmore » to that of the members of the LnBaCo{sub 4}O{sub 7} series, in spite of its oxygen excess. Its magnetic study shows that this phase, like CaBaCo{sub 4}O{sub 7}, is ferrimagnetic. Highlights: > Topotactic oxidation by means of electrochemistry and soft chemistry of the '114' orthorhombic cobaltite CaBaCo{sub 4}O{sub 7}. > This new phase, CaBaCo{sub 4}O{sub 7.5} shows an hexagonal structure, is closely related to that of orthorhombic mother phase CaBaCo{sub 4}O{sub 7}. > CaBaCo{sub 4}O{sub 7.5} is ferrimagnetic and exhibits an unusual magnetic hysteresis, due to defect pinning centers.« less

Authors:
 [1]; ; ; ; ;  [1]
  1. Laboratoire CRISMAT, UMR 6508 CNRS ENSICAEN, 6 bd Marechal Juin, 14050 Caen (France)
Publication Date:
OSTI Identifier:
21580255
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 184; Journal Issue: 9; Other Information: DOI: 10.1016/j.jssc.2011.07.039; PII: S0022-4596(11)00418-X; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DEFECTS; ELECTROCHEMISTRY; FERRIMAGNETISM; HYSTERESIS; MAGNETIC PROPERTIES; ORTHORHOMBIC LATTICES; OXIDATION; OXYGEN; CHEMICAL REACTIONS; CHEMISTRY; CRYSTAL LATTICES; CRYSTAL STRUCTURE; ELEMENTS; MAGNETISM; NONMETALS; PHYSICAL PROPERTIES

Citation Formats

Pralong, V., E-mail: valerie.pralong@ensicaen.fr, Caignaert, V., Sarkar, T., Lebedev, O.I., Duffort, V., and Raveau, B. Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo{sub 4}O{sub 7.50}. United States: N. p., 2011. Web. doi:10.1016/j.jssc.2011.07.039.
Pralong, V., E-mail: valerie.pralong@ensicaen.fr, Caignaert, V., Sarkar, T., Lebedev, O.I., Duffort, V., & Raveau, B. Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo{sub 4}O{sub 7.50}. United States. doi:10.1016/j.jssc.2011.07.039.
Pralong, V., E-mail: valerie.pralong@ensicaen.fr, Caignaert, V., Sarkar, T., Lebedev, O.I., Duffort, V., and Raveau, B. Thu . "Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo{sub 4}O{sub 7.50}". United States. doi:10.1016/j.jssc.2011.07.039.
@article{osti_21580255,
title = {Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo{sub 4}O{sub 7.50}},
author = {Pralong, V., E-mail: valerie.pralong@ensicaen.fr and Caignaert, V. and Sarkar, T. and Lebedev, O.I. and Duffort, V. and Raveau, B.},
abstractNote = {The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo{sub 4}O{sub 7}, using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo{sub 4}O{sub 7.50}, to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo{sub 4}O{sub 7}, is curiously similar to that of the members of the LnBaCo{sub 4}O{sub 7} series, in spite of its excess oxygen. Its magnetic study shows that this phase, like CaBaCo{sub 4}O{sub 7}, is ferrimagnetic with the same T{sub C} (60 K), but differently exhibits an unusual magnetic hysteresis. This exceptional behavior of CaBaCo{sub 4}O{sub 7} with respect to oxidation as well as the magnetic properties of CaBaCo{sub 4}O{sub 7.50} is interpreted in terms of the presence of defects due to oxidation. - Graphical Abstract: The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo{sub 4}O{sub 7}, using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo{sub 4}O{sub 7.50}, to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo{sub 4}O{sub 7}, is curiously similar to that of the members of the LnBaCo{sub 4}O{sub 7} series, in spite of its oxygen excess. Its magnetic study shows that this phase, like CaBaCo{sub 4}O{sub 7}, is ferrimagnetic. Highlights: > Topotactic oxidation by means of electrochemistry and soft chemistry of the '114' orthorhombic cobaltite CaBaCo{sub 4}O{sub 7}. > This new phase, CaBaCo{sub 4}O{sub 7.5} shows an hexagonal structure, is closely related to that of orthorhombic mother phase CaBaCo{sub 4}O{sub 7}. > CaBaCo{sub 4}O{sub 7.5} is ferrimagnetic and exhibits an unusual magnetic hysteresis, due to defect pinning centers.},
doi = {10.1016/j.jssc.2011.07.039},
journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = 9,
volume = 184,
place = {United States},
year = {2011},
month = {9}
}