Cation distribution and structural instability in Bi4-xLaxTi3O12

Minoru Osada; Masaru Tada; Masato Kakihana; Takayuki Watanabe; Hiroshi Funakubo

Cation distribution and structural instability in Bi_4-xLa_xTi₃O₁₂

Minoru Osada^*, Masaru Tada, Masato Kakihana, Takayuki Watanabe, Hiroshi Funakubo

^*Corresponding author for this work

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

158 Citations (Scopus)

Abstract

Raman spectra of Bi_4-xLa_xTi₃O₁₂ have been investigated. For an increasing degree of La doping, we find a substantial hardening of the vibration involving Bi atoms at the perovskite A site, whereas the Bi mode at the Bi₂O₂ layer is negligibly changed. From a comparison with a simple mass consideration, we identify a precise cation distribution, which indicates a pronounced site selectivity of La ions for the A site for x < ∼ 1. At room temperature, the lowest mode at 28 cm^-1 shows a significant softening with La doping. This behaviour resembles the temperature dependence in the nondoped material (at constant composition). A remarkable correlation is found between the soft-mode frequency and T_C for Bi_4-xLa_xTi₃O₁₂. We suggest that this correlation, as well as the soft-mode frequency for substituted materials, offers useful guidelines for designing materials in a controlled manner.

Original language	English
Pages (from-to)	5572-5575
Number of pages	4
Journal	Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume	40
Issue number	9 B
Publication status	Published - 2001 Sept
Externally published	Yes

Keywords

BiLaTiO
Cation distribution
Phase transition
Raman scattering
Soft mode

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

Cite this

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title = "Cation distribution and structural instability in Bi4-xLaxTi3O12",

abstract = "Raman spectra of Bi4-xLaxTi3O12 have been investigated. For an increasing degree of La doping, we find a substantial hardening of the vibration involving Bi atoms at the perovskite A site, whereas the Bi mode at the Bi2O2 layer is negligibly changed. From a comparison with a simple mass consideration, we identify a precise cation distribution, which indicates a pronounced site selectivity of La ions for the A site for x < ∼ 1. At room temperature, the lowest mode at 28 cm-1 shows a significant softening with La doping. This behaviour resembles the temperature dependence in the nondoped material (at constant composition). A remarkable correlation is found between the soft-mode frequency and TC for Bi4-xLaxTi3O12. We suggest that this correlation, as well as the soft-mode frequency for substituted materials, offers useful guidelines for designing materials in a controlled manner.",

keywords = "BiLaTiO, Cation distribution, Phase transition, Raman scattering, Soft mode",

author = "Minoru Osada and Masaru Tada and Masato Kakihana and Takayuki Watanabe and Hiroshi Funakubo",

year = "2001",

month = sep,

language = "English",

volume = "40",

pages = "5572--5575",

journal = "Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers",

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TY - JOUR

T1 - Cation distribution and structural instability in Bi4-xLaxTi3O12

AU - Osada, Minoru

AU - Tada, Masaru

AU - Kakihana, Masato

AU - Watanabe, Takayuki

AU - Funakubo, Hiroshi

PY - 2001/9

Y1 - 2001/9

N2 - Raman spectra of Bi4-xLaxTi3O12 have been investigated. For an increasing degree of La doping, we find a substantial hardening of the vibration involving Bi atoms at the perovskite A site, whereas the Bi mode at the Bi2O2 layer is negligibly changed. From a comparison with a simple mass consideration, we identify a precise cation distribution, which indicates a pronounced site selectivity of La ions for the A site for x < ∼ 1. At room temperature, the lowest mode at 28 cm-1 shows a significant softening with La doping. This behaviour resembles the temperature dependence in the nondoped material (at constant composition). A remarkable correlation is found between the soft-mode frequency and TC for Bi4-xLaxTi3O12. We suggest that this correlation, as well as the soft-mode frequency for substituted materials, offers useful guidelines for designing materials in a controlled manner.

AB - Raman spectra of Bi4-xLaxTi3O12 have been investigated. For an increasing degree of La doping, we find a substantial hardening of the vibration involving Bi atoms at the perovskite A site, whereas the Bi mode at the Bi2O2 layer is negligibly changed. From a comparison with a simple mass consideration, we identify a precise cation distribution, which indicates a pronounced site selectivity of La ions for the A site for x < ∼ 1. At room temperature, the lowest mode at 28 cm-1 shows a significant softening with La doping. This behaviour resembles the temperature dependence in the nondoped material (at constant composition). A remarkable correlation is found between the soft-mode frequency and TC for Bi4-xLaxTi3O12. We suggest that this correlation, as well as the soft-mode frequency for substituted materials, offers useful guidelines for designing materials in a controlled manner.

KW - BiLaTiO

KW - Cation distribution

KW - Phase transition

KW - Raman scattering

KW - Soft mode

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SN - 0021-4922

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JO - Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

JF - Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers

IS - 9 B

ER -

Cation distribution and structural instability in Bi_4-xLa_xTi₃O₁₂

Abstract

Keywords

ASJC Scopus subject areas

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