The role of iron in the formation of the magnetic structure and related properties of La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3)

Z. Klencsár, Z. Németh, E. Kuzmann, Z. Homonnay, A. Vértes, J. Hakl, K. Vad, S. Mészáros, A. Simopoulos, E. Devlin, G. Kallias, J. M. Grenéche, A. Cziráki, S. K. De

Research output: Contribution to journalArticle

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Abstract

La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3) samples were studied by means of AC magnetic susceptibility, magnetization, magnetoresistance and 57Fe Mössbauer spectrometry. Iron was found to take on a high spin 3d5-α electronic state in each of the samples, where α refers to a partly delocalized 3d electron. The compounds were found to exhibit a spin-cluster glass transition with a common transition temperature of ∼53 K. The spin-cluster glass transition is visualized in the 57Fe Mössbauer spectra as the slowing down of magnetic relaxation below ∼70 K, thereby showing that iron takes part in the formation of the glassy magnetic phase. The paramagnetic-like phase found at higher temperatures is identified below Tc≈195 K as being composed of weakly interacting, magnetically ordered nanosized clusters of magnetic ions in part with a magnetic moment oriented opposite to the net magnetic moment of the cluster. For each of the samples a considerable low-temperature negative magnetoresistance was found, whose magnitude in the studied range decreases with increasing iron concentration. The observed results obtained on the present compounds are qualitatively explained assuming that the absolute strengths of magnetic exchange interactions are subject to the relation {divides}JCo-Co{divides}Fe-Co{divide s}Fe-Fe{divides}.

Original languageEnglish
Pages (from-to)651-661
Number of pages11
JournalJournal of Magnetism and Magnetic Materials
Volume320
Issue number5
DOIs
Publication statusPublished - Mar 2008

Fingerprint

Magnetic structure
Iron
Magnetoresistance
Magnetic moments
iron
Glass transition
Magnetic relaxation
magnetic moments
Exchange interactions
Electronic states
Magnetic susceptibility
Spectrometry
Superconducting transition temperature
glass
Magnetization
magnetic relaxation
Ions
alternating current
Temperature
Electrons

Keywords

  • Magnetic relaxation
  • Magnetoresistance
  • Mössbauer-spectroscopy

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

The role of iron in the formation of the magnetic structure and related properties of La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3). / Klencsár, Z.; Németh, Z.; Kuzmann, E.; Homonnay, Z.; Vértes, A.; Hakl, J.; Vad, K.; Mészáros, S.; Simopoulos, A.; Devlin, E.; Kallias, G.; Grenéche, J. M.; Cziráki, A.; De, S. K.

In: Journal of Magnetism and Magnetic Materials, Vol. 320, No. 5, 03.2008, p. 651-661.

Research output: Contribution to journalArticle

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abstract = "La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3) samples were studied by means of AC magnetic susceptibility, magnetization, magnetoresistance and 57Fe M{\"o}ssbauer spectrometry. Iron was found to take on a high spin 3d5-α electronic state in each of the samples, where α refers to a partly delocalized 3d electron. The compounds were found to exhibit a spin-cluster glass transition with a common transition temperature of ∼53 K. The spin-cluster glass transition is visualized in the 57Fe M{\"o}ssbauer spectra as the slowing down of magnetic relaxation below ∼70 K, thereby showing that iron takes part in the formation of the glassy magnetic phase. The paramagnetic-like phase found at higher temperatures is identified below Tc≈195 K as being composed of weakly interacting, magnetically ordered nanosized clusters of magnetic ions in part with a magnetic moment oriented opposite to the net magnetic moment of the cluster. For each of the samples a considerable low-temperature negative magnetoresistance was found, whose magnitude in the studied range decreases with increasing iron concentration. The observed results obtained on the present compounds are qualitatively explained assuming that the absolute strengths of magnetic exchange interactions are subject to the relation {divides}JCo-Co{divides}Fe-Co{divide s}Fe-Fe{divides}.",
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T1 - The role of iron in the formation of the magnetic structure and related properties of La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3)

AU - Klencsár, Z.

AU - Németh, Z.

AU - Kuzmann, E.

AU - Homonnay, Z.

AU - Vértes, A.

AU - Hakl, J.

AU - Vad, K.

AU - Mészáros, S.

AU - Simopoulos, A.

AU - Devlin, E.

AU - Kallias, G.

AU - Grenéche, J. M.

AU - Cziráki, A.

AU - De, S. K.

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N2 - La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3) samples were studied by means of AC magnetic susceptibility, magnetization, magnetoresistance and 57Fe Mössbauer spectrometry. Iron was found to take on a high spin 3d5-α electronic state in each of the samples, where α refers to a partly delocalized 3d electron. The compounds were found to exhibit a spin-cluster glass transition with a common transition temperature of ∼53 K. The spin-cluster glass transition is visualized in the 57Fe Mössbauer spectra as the slowing down of magnetic relaxation below ∼70 K, thereby showing that iron takes part in the formation of the glassy magnetic phase. The paramagnetic-like phase found at higher temperatures is identified below Tc≈195 K as being composed of weakly interacting, magnetically ordered nanosized clusters of magnetic ions in part with a magnetic moment oriented opposite to the net magnetic moment of the cluster. For each of the samples a considerable low-temperature negative magnetoresistance was found, whose magnitude in the studied range decreases with increasing iron concentration. The observed results obtained on the present compounds are qualitatively explained assuming that the absolute strengths of magnetic exchange interactions are subject to the relation {divides}JCo-Co{divides}Fe-Co{divide s}Fe-Fe{divides}.

AB - La0.8Sr0.2Co1-xFex O3 (x=0.15, 0.2, 0.3) samples were studied by means of AC magnetic susceptibility, magnetization, magnetoresistance and 57Fe Mössbauer spectrometry. Iron was found to take on a high spin 3d5-α electronic state in each of the samples, where α refers to a partly delocalized 3d electron. The compounds were found to exhibit a spin-cluster glass transition with a common transition temperature of ∼53 K. The spin-cluster glass transition is visualized in the 57Fe Mössbauer spectra as the slowing down of magnetic relaxation below ∼70 K, thereby showing that iron takes part in the formation of the glassy magnetic phase. The paramagnetic-like phase found at higher temperatures is identified below Tc≈195 K as being composed of weakly interacting, magnetically ordered nanosized clusters of magnetic ions in part with a magnetic moment oriented opposite to the net magnetic moment of the cluster. For each of the samples a considerable low-temperature negative magnetoresistance was found, whose magnitude in the studied range decreases with increasing iron concentration. The observed results obtained on the present compounds are qualitatively explained assuming that the absolute strengths of magnetic exchange interactions are subject to the relation {divides}JCo-Co{divides}Fe-Co{divide s}Fe-Fe{divides}.

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