Characterization of films of La 1-xSr xMnO 3-δ grown by means of metal organic chemical vapor deposition

J. J. Heremans, M. Carris, S. Watts, X. Yu, K. H. Dahmen, S. Von Molnár

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Abstract

An effort to develop La manganites for possible sensor applications has led to the successful growth of La, 1-xB xMnO 3-δ (B=Sr, Ca) thin films on single crystal MgO, Al 2O 3, and LaAlO 3 substrates. Here we concentrate on Sr-doped material on LaAlO 3 with Curie temperature T c=262±2 K. T c was determined from magnetization measurements using Arrott plots, and agrees well with the observed resistivity peak in zero applied magnetic field (H). This T c corresponds closely to a Sr content x=0.17 reported in bulk materials. At H=60 kOe the maximum magnetoresistance Δρ/ ρ≈0.95. No discernible hysteresis, as might be expected for structural phase transitions, was observed. When plotted as a function of reduced temperature T/T c, the magnetization extrapolated , to zero H is best fit by a Brillouin function with an effective spin value 〈S〉 much larger than the 〈S〉= 1.9 indicated by the composition. This may be indicative of magnetic polaron formation, especially near the magnetic and transport transition temperatures. At temperatures far below T c there is an increase in resistivity of the thin films, which is considerably modified by the application of a field of 50 kOe. The conductivity, however, remains finite as the temperature approaches zero, indicating transport in states close to but above the mobility edge.

Original languageEnglish
Pages (from-to)4967-4969
Number of pages3
JournalJournal of Applied Physics
Volume81
Issue number8 PART 2B
Publication statusPublished - 15 Apr 1997
Externally publishedYes

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ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)
  • Physics and Astronomy(all)

Cite this

Heremans, J. J., Carris, M., Watts, S., Yu, X., Dahmen, K. H., & Von Molnár, S. (1997). Characterization of films of La 1-xSr xMnO 3-δ grown by means of metal organic chemical vapor deposition. Journal of Applied Physics, 81(8 PART 2B), 4967-4969.