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Keywords:

  • Manganites;
  • Transport properties;
  • Multicomponent source;
  • Depth profile;
  • Texture

Abstract

La0.9Sr0.1MnO3 (LSMO) films are grown on LaAlO3(100) substrates through metal-organic (MO)CVD using “second generation” precursors of Sr, La, and Mn. An in-situ novel MOCVD strategy is adopted which involves the use of two different molten mixtures consisting of the La(hfa)3•diglyme and Sr(hfa)2•tetraglyme adducts as La and Sr sources, respectively, and Mn(hfa)2•tmeda or Mn(tmhd)3 as Mn precursor [Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, diglyme = bis(2-methoxyethyl)ether, tetraglyme = 2,5,8,11,14-pentaoxapentadecane, tmeda = N,N,N′,N′-tetramethylethylendiamine and H-tmhd = 2,2,6,6-tetramethyl-3,5-heptandione]. The X-ray diffraction (XRD) patterns show that the films are c-axis oriented. Pole figures are applied as a simple non-invasive tool to assess the textural nature of these LSMO films. The morphology is investigated using the scanning electron microscopy (SEM) and atomic force microscopy (AFM) that reveal the presence of grains, 300 nm average dimensions, and a root mean square (rms) surface roughness of 21 nm. Chemical composition through energy-dispersive X-ray (EDX) analysis indicates that the films possess a stoichiometry of about 0.9:0.1:1 ratio, while X-ray photoelectron spectroscopy (XPS) depth profiles are used to assess the vertical compositional homogeneity. The ferromagnetic/paramagnetic and metallic/insulating transition temperatures are determined by standard four-contact resistivity versus temperature measurements.