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Title: Synthesis and characterization of K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd)

Abstract

K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd) has been synthesized at 1173 or 1223 K in air using citric acid (CA) and ethylene glycol (EG). CaLnCoO{sub 4} (Ln = Sm and Gd) has an orthorhombic structure with the space group Bmab. The average particle sizes are approximately 300 nm for CaSmCoO{sub 4} and approximately 170 nm for CaGdCoO{sub 4}, respectively. The global instability index (GII) indicates that the crystal structure of CaGdCoO{sub 4} is more stable than that of CaSmCoO{sub 4}. CaLnCoO{sub 4} (Ln = Sm and Gd) is a p-type semiconductor and shows paramagnetic behavior above 5 K. The 1/{chi}-T curve of CaSmCoO{sub 4} deviates from the Curie-Weiss law, whereas the 1/{chi}-T curve of CaGdCoO{sub 4} follows the Curie-Weiss law in the temperature range of 5 {<=} T {<=} 300 K. From the values of the observed effective magnetic moment ({mu} {sub eff}) of CaLnCoO{sub 4} (Ln = Sm and Gd), it is considered that the spin state of the Co{sup 3+} ion is low.

Authors:
 [1];  [2];  [3]
  1. Research Laboratory for Surface Science, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530 (Japan). E-mail: htaguchi@cc.okayama-u.ac.jp
  2. Kyoto Prefecture Collaboration of Regional Entities for the Advancement of Technological Excellence, JST, 1-7 Hikari-dai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan)
  3. Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University, 1-3 Tatara-miyakotani, Kyo-tanabe, Kyoto 610-0321 (Japan)
Publication Date:
OSTI Identifier:
21000617
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 42; Journal Issue: 4; Other Information: DOI: 10.1016/j.materresbull.2006.08.004; PII: S0025-5408(06)00320-5; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHEMICAL PREPARATION; CITRIC ACID; COBALT IONS; CURIE-WEISS LAW; GLYCOLS; MAGNETIC MOMENTS; MAGNETIC PROPERTIES; ORTHORHOMBIC LATTICES; OXIDES; PARAMAGNETISM; PARTICLE SIZE; SEMICONDUCTOR MATERIALS; SOL-GEL PROCESS; SPACE GROUPS; SPIN; X-RAY DIFFRACTION

Citation Formats

Taguchi, Hideki, Nakade, Katsuyuki, and Hirota, Ken. Synthesis and characterization of K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd). United States: N. p., 2007. Web. doi:10.1016/j.materresbull.2006.08.004.
Taguchi, Hideki, Nakade, Katsuyuki, & Hirota, Ken. Synthesis and characterization of K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd). United States. doi:10.1016/j.materresbull.2006.08.004.
Taguchi, Hideki, Nakade, Katsuyuki, and Hirota, Ken. Thu . "Synthesis and characterization of K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd)". United States. doi:10.1016/j.materresbull.2006.08.004.
@article{osti_21000617,
title = {Synthesis and characterization of K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd)},
author = {Taguchi, Hideki and Nakade, Katsuyuki and Hirota, Ken},
abstractNote = {K{sub 2}NiF{sub 4}-type CaLnCoO{sub 4} (Ln = Sm and Gd) has been synthesized at 1173 or 1223 K in air using citric acid (CA) and ethylene glycol (EG). CaLnCoO{sub 4} (Ln = Sm and Gd) has an orthorhombic structure with the space group Bmab. The average particle sizes are approximately 300 nm for CaSmCoO{sub 4} and approximately 170 nm for CaGdCoO{sub 4}, respectively. The global instability index (GII) indicates that the crystal structure of CaGdCoO{sub 4} is more stable than that of CaSmCoO{sub 4}. CaLnCoO{sub 4} (Ln = Sm and Gd) is a p-type semiconductor and shows paramagnetic behavior above 5 K. The 1/{chi}-T curve of CaSmCoO{sub 4} deviates from the Curie-Weiss law, whereas the 1/{chi}-T curve of CaGdCoO{sub 4} follows the Curie-Weiss law in the temperature range of 5 {<=} T {<=} 300 K. From the values of the observed effective magnetic moment ({mu} {sub eff}) of CaLnCoO{sub 4} (Ln = Sm and Gd), it is considered that the spin state of the Co{sup 3+} ion is low.},
doi = {10.1016/j.materresbull.2006.08.004},
journal = {Materials Research Bulletin},
number = 4,
volume = 42,
place = {United States},
year = {Thu Apr 12 00:00:00 EDT 2007},
month = {Thu Apr 12 00:00:00 EDT 2007}
}