Single crystal growth and magnetic properties of La2-xMxCoO4 (M=Ca, Ba)

Kazumasa Horigane; Toru Uchida; Jun Akimitsu

doi:10.1016/j.physb.2006.01.423

Single crystal growth and magnetic properties of La_2-xM_xCoO₄ (M=Ca, Ba)

Kazumasa Horigane, Toru Uchida, Jun Akimitsu

Research output: Contribution to journal › Article › peer-review

10 Citations (Scopus)

Abstract

Magnetic properties were investigated for single crystals of La_2-xCa_xCoO₄ ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.8 ) and for polycrystalline samples of La_2-xBa_xCoO₄ ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.9 ) . In the Ca system, the effective moment μ_eff decreased with increasing x from 4.0 μ_B ( x = 0.5 ) to 3.0 μ_B ( x = 0.7 - 0.8 ), accompanied by a steep reduction of Weiss temperature Θ. These drastic changes of the magnetic properties suggest a spin-state transition of the Co³⁺ ions from the high-spin state to the intermediate-spin state. On the other hand, the effective moment of La_2-xBa_xCoO₄ was almost 4.0 μ_B and there is no change of Weiss temperature Θ. These facts suggest that the intermediate-spin state is related to the Co-O bond length, i.e. crystal fields.

Original language	English
Pages (from-to)	334-336
Number of pages	3
Journal	Physica B: Condensed Matter
Volume	378-380
Issue number	SPEC. ISS.
DOIs	https://doi.org/10.1016/j.physb.2006.01.423
Publication status	Published - May 1 2006
Externally published	Yes

Keywords

Cobalt oxides
Intermediate-spin state
KNiF type

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Electrical and Electronic Engineering

Access to Document

10.1016/j.physb.2006.01.423

Cite this

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title = "Single crystal growth and magnetic properties of La2-xMxCoO4 (M=Ca, Ba)",

abstract = "Magnetic properties were investigated for single crystals of La2-xCaxCoO4 ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.8 ) and for polycrystalline samples of La2-xBaxCoO4 ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.9 ) . In the Ca system, the effective moment μeff decreased with increasing x from 4.0 μB ( x = 0.5 ) to 3.0 μB ( x = 0.7 - 0.8 ), accompanied by a steep reduction of Weiss temperature Θ. These drastic changes of the magnetic properties suggest a spin-state transition of the Co3+ ions from the high-spin state to the intermediate-spin state. On the other hand, the effective moment of La2-xBaxCoO4 was almost 4.0 μB and there is no change of Weiss temperature Θ. These facts suggest that the intermediate-spin state is related to the Co-O bond length, i.e. crystal fields.",

keywords = "Cobalt oxides, Intermediate-spin state, KNiF type",

author = "Kazumasa Horigane and Toru Uchida and Jun Akimitsu",

year = "2006",

month = may,

day = "1",

doi = "10.1016/j.physb.2006.01.423",

language = "English",

volume = "378-380",

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journal = "Physica B: Condensed Matter",

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T1 - Single crystal growth and magnetic properties of La2-xMxCoO4 (M=Ca, Ba)

AU - Horigane, Kazumasa

AU - Uchida, Toru

AU - Akimitsu, Jun

PY - 2006/5/1

Y1 - 2006/5/1

N2 - Magnetic properties were investigated for single crystals of La2-xCaxCoO4 ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.8 ) and for polycrystalline samples of La2-xBaxCoO4 ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.9 ) . In the Ca system, the effective moment μeff decreased with increasing x from 4.0 μB ( x = 0.5 ) to 3.0 μB ( x = 0.7 - 0.8 ), accompanied by a steep reduction of Weiss temperature Θ. These drastic changes of the magnetic properties suggest a spin-state transition of the Co3+ ions from the high-spin state to the intermediate-spin state. On the other hand, the effective moment of La2-xBaxCoO4 was almost 4.0 μB and there is no change of Weiss temperature Θ. These facts suggest that the intermediate-spin state is related to the Co-O bond length, i.e. crystal fields.

AB - Magnetic properties were investigated for single crystals of La2-xCaxCoO4 ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.8 ) and for polycrystalline samples of La2-xBaxCoO4 ( 0.5 {less-than or slanted equal to} x {less-than or slanted equal to} 0.9 ) . In the Ca system, the effective moment μeff decreased with increasing x from 4.0 μB ( x = 0.5 ) to 3.0 μB ( x = 0.7 - 0.8 ), accompanied by a steep reduction of Weiss temperature Θ. These drastic changes of the magnetic properties suggest a spin-state transition of the Co3+ ions from the high-spin state to the intermediate-spin state. On the other hand, the effective moment of La2-xBaxCoO4 was almost 4.0 μB and there is no change of Weiss temperature Θ. These facts suggest that the intermediate-spin state is related to the Co-O bond length, i.e. crystal fields.

KW - Cobalt oxides

KW - Intermediate-spin state

KW - KNiF type

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