Orthorhombic distortion in Ca2-xGdxMnO4

Junichi Takahashi; Hidenori Nakada; Hirohisa Satoh; Naoki Kamegashira

doi:10.1016/j.jallcom.2004.12.150

Orthorhombic distortion in Ca_2-xGd_xMnO₄

Junichi Takahashi, Hidenori Nakada, Hirohisa Satoh, Naoki Kamegashira

Division of Inorganic Material Research

Research output: Contribution to journal › Conference article › peer-review

4 Citations (Scopus)

Abstract

The crystal structure of the polycrystalline Ca_2-xGd _xMnO₄ has been investigated by Rietveld method using X-ray diffraction patterns measured at room temperature. Within the limited substitution range, 0 < x < 0.45, Ca_2-xGd_xMnO ₄ has the K₂NiF₄-type structure. In x = 0.2 X-ray spectrum shows the tetragonal primitive structure (space group I4/mmm). In the range of x from 0.35 to 0.45 an orthorhombic superstructure (space group Pccn), whose unit cell relates to the tetragonal primitive structure with a _o ≈ b_o ≈ 2a_t, c_o ≈ c _t, is refined. The orthorhombic superstructure contains the oxygen connected MnO₆ octahedra with a different tilt angle between x- and y-axes of the orthorhombic unit cell. The magnitude of the rotation of the MnO₆ octahedra around x-axis increases with increasing the substitution of x in Ca_2-xGd_xMnO₄, and that around y-axis shows the maximum at x = 0.4.

Original language	English
Pages (from-to)	598-602
Number of pages	5
Journal	Journal of Alloys and Compounds
Volume	408-412
DOIs	https://doi.org/10.1016/j.jallcom.2004.12.150
Publication status	Published - 2006 Feb 9
Event	Proceedings of the Rare Earths'04 in Nara, Japan - Duration: 2004 Nov 7 → 2004 Nov 12

Keywords

Calcium rare-earth manganate
KNiF-type oxides
Orthorhombic structure
Oxygen octahedron

ASJC Scopus subject areas

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

Access to Document

10.1016/j.jallcom.2004.12.150

Cite this

@article{6c2f6e27cccb4571868855b5a9f086a1,

title = "Orthorhombic distortion in Ca2-xGdxMnO4",

abstract = "The crystal structure of the polycrystalline Ca2-xGd xMnO4 has been investigated by Rietveld method using X-ray diffraction patterns measured at room temperature. Within the limited substitution range, 0 < x < 0.45, Ca2-xGdxMnO 4 has the K2NiF4-type structure. In x = 0.2 X-ray spectrum shows the tetragonal primitive structure (space group I4/mmm). In the range of x from 0.35 to 0.45 an orthorhombic superstructure (space group Pccn), whose unit cell relates to the tetragonal primitive structure with a o ≈ bo ≈ 2at, co ≈ c t, is refined. The orthorhombic superstructure contains the oxygen connected MnO6 octahedra with a different tilt angle between x- and y-axes of the orthorhombic unit cell. The magnitude of the rotation of the MnO6 octahedra around x-axis increases with increasing the substitution of x in Ca2-xGdxMnO4, and that around y-axis shows the maximum at x = 0.4.",

keywords = "Calcium rare-earth manganate, KNiF-type oxides, Orthorhombic structure, Oxygen octahedron",

author = "Junichi Takahashi and Hidenori Nakada and Hirohisa Satoh and Naoki Kamegashira",

note = "Funding Information: This work was supported by the Grant-in-Aid for Scientific Research by the Japan Society for the Promotion of Science.; Proceedings of the Rare Earths'04 in Nara, Japan ; Conference date: 07-11-2004 Through 12-11-2004",

year = "2006",

month = feb,

day = "9",

doi = "10.1016/j.jallcom.2004.12.150",

language = "English",

volume = "408-412",

pages = "598--602",

journal = "Journal of Alloys and Compounds",

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TY - JOUR

T1 - Orthorhombic distortion in Ca2-xGdxMnO4

AU - Takahashi, Junichi

AU - Nakada, Hidenori

AU - Satoh, Hirohisa

AU - Kamegashira, Naoki

N1 - Funding Information: This work was supported by the Grant-in-Aid for Scientific Research by the Japan Society for the Promotion of Science.

PY - 2006/2/9

Y1 - 2006/2/9

N2 - The crystal structure of the polycrystalline Ca2-xGd xMnO4 has been investigated by Rietveld method using X-ray diffraction patterns measured at room temperature. Within the limited substitution range, 0 < x < 0.45, Ca2-xGdxMnO 4 has the K2NiF4-type structure. In x = 0.2 X-ray spectrum shows the tetragonal primitive structure (space group I4/mmm). In the range of x from 0.35 to 0.45 an orthorhombic superstructure (space group Pccn), whose unit cell relates to the tetragonal primitive structure with a o ≈ bo ≈ 2at, co ≈ c t, is refined. The orthorhombic superstructure contains the oxygen connected MnO6 octahedra with a different tilt angle between x- and y-axes of the orthorhombic unit cell. The magnitude of the rotation of the MnO6 octahedra around x-axis increases with increasing the substitution of x in Ca2-xGdxMnO4, and that around y-axis shows the maximum at x = 0.4.

AB - The crystal structure of the polycrystalline Ca2-xGd xMnO4 has been investigated by Rietveld method using X-ray diffraction patterns measured at room temperature. Within the limited substitution range, 0 < x < 0.45, Ca2-xGdxMnO 4 has the K2NiF4-type structure. In x = 0.2 X-ray spectrum shows the tetragonal primitive structure (space group I4/mmm). In the range of x from 0.35 to 0.45 an orthorhombic superstructure (space group Pccn), whose unit cell relates to the tetragonal primitive structure with a o ≈ bo ≈ 2at, co ≈ c t, is refined. The orthorhombic superstructure contains the oxygen connected MnO6 octahedra with a different tilt angle between x- and y-axes of the orthorhombic unit cell. The magnitude of the rotation of the MnO6 octahedra around x-axis increases with increasing the substitution of x in Ca2-xGdxMnO4, and that around y-axis shows the maximum at x = 0.4.

KW - Calcium rare-earth manganate

KW - KNiF-type oxides

KW - Orthorhombic structure

KW - Oxygen octahedron

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JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

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