Effect of vacuum annealing on oxygen stoichiometry and resistivity of sol-gel derived La0.7Sr0.3MnO3-δ films

Honglyoul Ju, Kannan M. Krishnan

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

We have, studied the dependence of the resistivity and magnetoresistance (MR) of epitaxial (0 0 1) La0.7Sr0.3MnO3-δ/(0 0 1) LaAlO3 films on controlled vacuum annealing. First, La0.7Sr0.3MnO3-δ films grown by sol-gel process were annealed at O2 (1 atm. oxygen)/1170 K/1 h (we call this as-prepared films); subsequently, these as-prepared films were annealed in vacuum (∼10-6 torr/2 h) at different temperatures, i.e. 720 K, 770 K, 820 K, 920 K, to systematically reduce the oxygen stoichiometry. The resistivity increases systematically with increasing annealing temperature in accord with oxygen content variation. The resistivity shows a metallic behavior (as-prepared films), metal-insulator transitions (films annealed at 720 K, 770 K) and an insulating behavior (films annealed at 820 K, 920 K). Significant MR is observed predominantly near the resistivity peak for the metallic films and at low temperature for the insulating films. These observations demonstrate that the oxygen content, the resistivity and MR behavior of manganese oxides are precisely controllable via vacuum annealing.

Original languageEnglish
Pages (from-to)419-423
Number of pages5
JournalSolid State Communications
Volume104
Issue number7
DOIs
Publication statusPublished - 1997 Jan 1

Fingerprint

Stoichiometry
Sol-gels
stoichiometry
gels
Vacuum
Annealing
Oxygen
vacuum
electrical resistivity
annealing
oxygen
Magnetoresistance
Metallic films
Metal insulator transition
Manganese oxide
manganese oxides
sol-gel processes
metal films
Temperature
Sol-gel process

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics
  • Materials Chemistry

Cite this

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abstract = "We have, studied the dependence of the resistivity and magnetoresistance (MR) of epitaxial (0 0 1) La0.7Sr0.3MnO3-δ/(0 0 1) LaAlO3 films on controlled vacuum annealing. First, La0.7Sr0.3MnO3-δ films grown by sol-gel process were annealed at O2 (1 atm. oxygen)/1170 K/1 h (we call this as-prepared films); subsequently, these as-prepared films were annealed in vacuum (∼10-6 torr/2 h) at different temperatures, i.e. 720 K, 770 K, 820 K, 920 K, to systematically reduce the oxygen stoichiometry. The resistivity increases systematically with increasing annealing temperature in accord with oxygen content variation. The resistivity shows a metallic behavior (as-prepared films), metal-insulator transitions (films annealed at 720 K, 770 K) and an insulating behavior (films annealed at 820 K, 920 K). Significant MR is observed predominantly near the resistivity peak for the metallic films and at low temperature for the insulating films. These observations demonstrate that the oxygen content, the resistivity and MR behavior of manganese oxides are precisely controllable via vacuum annealing.",
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Effect of vacuum annealing on oxygen stoichiometry and resistivity of sol-gel derived La0.7Sr0.3MnO3-δ films. / Ju, Honglyoul; Krishnan, Kannan M.

In: Solid State Communications, Vol. 104, No. 7, 01.01.1997, p. 419-423.

Research output: Contribution to journalArticle

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AB - We have, studied the dependence of the resistivity and magnetoresistance (MR) of epitaxial (0 0 1) La0.7Sr0.3MnO3-δ/(0 0 1) LaAlO3 films on controlled vacuum annealing. First, La0.7Sr0.3MnO3-δ films grown by sol-gel process were annealed at O2 (1 atm. oxygen)/1170 K/1 h (we call this as-prepared films); subsequently, these as-prepared films were annealed in vacuum (∼10-6 torr/2 h) at different temperatures, i.e. 720 K, 770 K, 820 K, 920 K, to systematically reduce the oxygen stoichiometry. The resistivity increases systematically with increasing annealing temperature in accord with oxygen content variation. The resistivity shows a metallic behavior (as-prepared films), metal-insulator transitions (films annealed at 720 K, 770 K) and an insulating behavior (films annealed at 820 K, 920 K). Significant MR is observed predominantly near the resistivity peak for the metallic films and at low temperature for the insulating films. These observations demonstrate that the oxygen content, the resistivity and MR behavior of manganese oxides are precisely controllable via vacuum annealing.

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