MOCVD of BiFeO₃ Thin Films on SrTiO₃

Abstract

Bi-Fe-O thin films are grown by liquid-injection metal-organic (MO)CVD on (001) SrTiO 3 substrates using two different bismuth precursors, Bi(tmhd) 3 and Bi(mmp) 3 . The precursor Bi(mmp) 3 is found to be more effective for Bi incorporation in the films. Epitaxial BiFeO 3 films are obtained and no evidence for secondary phases such as Fe 2 O 3 or Bi 2 O 3 is found by X-ray diffraction (XRD) or transmission electron microscopy (TEM) studies. However, the presence of a multiple binding environment for Fe 3+ is shown from the X-ray photoelectron spectroscopy (XPS) analyses.

Crystallization engineering as a route to epitaxial strain control

“…Here, we choose BiFeO 3 as a model perovskite material, the epitaxial thin films of which have been well studied and can be grown using various techniques such as physical vapor deposition (e.g., pulsed laser deposition, PLD, 9 and RF sputtering 10 ), metal-organic chemical vapor deposition (MOCVD), 11,12 and molecular beam epitaxy. 13 Co-existence of both ferroelectric and magnetic ordering makes BiFeO 3 one of the most intriguing electronic materials.…”

Spray pyrolysis deposited multiferroic BiFeO3 films

“…Lower temperature or higher pressure is more conducive for Bi 2 10,[14][15][16] In the present BFO film oxygenation and dense surface morphology suppress the formation of oxygen vacancies, i.e., valence fluctuations of Fe ions and grain boundary density, respectively. This results in high resistivity of the order of 10 12 ⍀ cm, much better than that of other BFO films ͑10 9 ⍀ cm͒.…”

“…As mentioned earlier, the present thicker BFO film having a R3m structure is less rhombohedrally distorted than R3c, 8 and this suppresses the spatially modulated spin structure and hence causes weak ferromagnetism due to spin canting. 6,[8][9][10] However, additional magnetization due to some kind of magnetic layer having ferromagnetic-Fe 2 O 3 rich nanoclusters or precipitates can not be ruled out because ␥-Fe 2 O 3 have large magnetization of ϳ400 emu/ cc. [14][15][16] To search the microscopic magnetic clusters ͑e.g., Fe 2 O 3 ͒ as the source of large anomalous magnetization we carried out TEM investigation ͓Figs.…”

“…6 Thin films of BFO with the desired and reproducible multiferroic properties have been prepared by pulsed laser deposition, sputtering, sol gel, chemical solution deposition, and so on. 5,[7][8][9][10] However, the multiferroic behavior varied remarkably in the samples and has been attributed to the synthesis techniques and processing parameters seem to play a decisive role on the multiferroic properties of BFO. In spray pyrolysis technique various synthesis parameters can be easily manipulated and it has many advantages, such as lower deposition temperature, precise control of composition, and better chemical homogeneity over large area.…”

Synthesis of multifunctional multiferroic materials from metalorganics

“…The use of a solvent raises the possibility of organic contamination in the films. Also, particularly in the case of mixed precursors, appropriate solvent needs to be determined using solubility and viscosity tests [48]. In a band-flash type of setup, the choice of solvent becomes more relaxed [102,103] (Fig.…”