Titanium doping of BiFeO₃ ceramics and identification of minor phases by Raman spectroscopy

Abstract

Titanium substitution can improve the multiferroic properties of bismuth ferrite materials, albeit the structural changes that this dopant produces in the perovskite structure of BiFeO3 are still not well understood. Due to its high sensitivity, Raman spectroscopy can be a useful tool for trailing the dopant incorporation. In this work, we study the Raman spectra of undoped and Ti4+‐doped BiFeO3 ceramics that also contain small amounts of secondary phases – as it is usual for materials of this system. The micro‐Raman study together with a rigorous derivative analysis of the experimental Raman spectra recorded at low temperature (73 K) enables, for the first time, the identification of the Raman bands associated with the BiFeO3 phase together with those belonging to the minor secondary phases. The comparison between the Raman spectra of the undoped and the Ti4+‐doped materials indicates that some of the titanium added to the composition interacts with the secondary phases while only a partial amount of this dopant actually incorporates into the BiFeO3 phase. Copyright © 2017 John Wiley & Sons, Ltd.

Nanostructure stabilization by low-temperature dopant pinning in multiferroic BiFeO3-based thin films produced by aqueous chemical solution deposition

“…The results initially indicate that all compositions crystallize with a rhombohedrally distorted perovskite structure with the mentioned R3c space group. The specific bands of the Bi 2 Fe 4 O 9 and Bi 25 FeO 39 phases (as, for example, identified by Bernardo et al) 43 cannot be detected, again validating the competence of the processing approach to prevent the formation of secondary phases in the crystallized films. The BNFO and the BNFTO films besides show the presence of some extra peaks at approximately 192, 276, 360 and 537 cm À1 (marked with an asterisk in Fig.…”

Combination of structural and microstructural effects in the multiferroic response of Nd and Ti co-doped BiFeO3 bulk ceramics

“…Ceramic bulk samples with nominal composition Bi 0.85 Nd 0.15 Fe 0.95 Ti 0.05 O 3.025 (referenced hereafter as BNFTO) were prepared using a standard solid state reaction procedure as described elsewhere [35]. The corresponding amounts of the oxide precursors, Bi 2 O 3 (Aldrich, 99.9 %), Fe 2 O 3 (Sigma-Aldrich, > 99 %), Nd 2 O 3 (Aldrich 99.9 %) and TiO 2 (anatase structure, Sigma-Aldrich, > 99%) were weighed and subjected to 2 hours of attrition milling with YSZ balls and ethanol as liquid medium.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XII

“…Titanium substitution can improve the multiferroic properties of bismuth ferrite materials, even though the structural changes that this dopant produces in the perovskite structure of BiFeO 3 are still not well understood. The comparison between the Raman spectra of the undoped and the Ti 4+ ‐doped materials indicates that some of the titanium added interacts with the secondary phases while only a partial amount of this dopant actually incorporates into the BiFeO 3 phase . Livneh, Dumcenco, and Pinkas determined the alloy composition of Mo x W 1 ‐ x S 2 from its low wavenumber Raman spectrum.…”

“…The comparison between the Raman spectra of the undoped and the Ti 4+ -doped materials indicates that some of the titanium added interacts with the secondary phases while only a partial amount of this dopant actually incorporates into the BiFeO 3 phase. [179] Livneh, Dumcenco, and Pinkas determined the alloy composition of Mo x W 1x S 2 from its low wavenumber Raman spectrum. The results provide a convenient and reliable means for systematically determining sample Mo/W composition.…”