Raman scattering from La-substituted BiFeO{sub 3}-PbTiO{sub 3}

Journal Article · Thu Sep 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.07.014· OSTI ID:21580274

Mishra, K K; Sivasubramanian, V; Sarguna, R M; Ravindran, T R ^[1]

---

1. Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

Polycrystalline samples of pure BiFeO{sub 3}-PbTiO{sub 3} (BF-PT) and those upon substituting Bi by La up to 50% (x{<=}0.5) were synthesized using a solid-state reaction method. A composition-driven tetragonal-cubic transition, identified from X-ray diffraction, was found to occur at x=0.4. We report the phonon spectra of pure and La-substituted BF-PT and its assignment. From the behavior of total Raman intensity, the origin of the symmetry-forbidden Raman spectra is identified to lie in substitutional disorder. The dependence of splitting of A{sub 1}-E modes and that of the LO-TO modes on composition are obtained and their consequences on ionicity are discussed. - Graphical abstract: Raman spectrum of the cubic phase (x{>=}0.4) of La-substituted BF-PT [0.5(Bi{sub 1-x}La{sub x}FeO{sub 3})0.5(PbTiO{sub 3})] consists of 7 modes, while group theory does not predict any Raman active phonon. Highlights: > Composition-driven tetragonal-cubic transition in La-substituted BF-PT. > Phonon spectra in the tetragonal phase assigned. > A{sub 1}-E anisotropy splitting of phonons decreases upon La-substitution. > Increase in LO-TO splitting at larger La composition due to higher ionicity.

• OSTI ID: 21580274
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 9; Other Information: DOI: 10.1016/j.jssc.2011.07.014; PII: S0022-4596(11)00383-5; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALLOCATIONS
ANISOTROPY
CRYSTAL-PHASE TRANSFORMATIONS
GROUP THEORY
LEAD COMPOUNDS
PHONONS
POLYCRYSTALS
RAMAN EFFECT
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SOLIDS
TITANATES
X-RAY DIFFRACTION
COHERENT SCATTERING
CRYSTALS
DIFFRACTION
LASER SPECTROSCOPY
MATHEMATICS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
QUASI PARTICLES
SCATTERING
SPECTRA
SPECTROSCOPY
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS