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Title: Effect of Dy-substitution on the structural, vibrational, and multiferroic properties of BiFeO{sub 3} nanoparticles

Dysprosium (Dy) modified BiFeO{sub 3} [Bi{sub 1−x}Dy{sub x}FeO{sub 3} (x = 0.05, 0.10, and 0.15)] nanoparticles have been synthesized by a low temperature co-precipitation method. Rietveld analysis of X-ray diffraction data reveals a transformation from rhombohedral structure to orthorhombic structure with increase in the Dy concentration. From the transmission electron microscopy analysis, it is observed that the particle sizes of Bi{sub 1−x}Dy{sub x}FeO{sub 3} (x = 0.05, 0.10, and 0.15) nanoparticles range between 50–70, 40–50, and 30–50 nm, respectively. Raman spectra of Bi{sub 1−x}Dy{sub x}FeO{sub 3} (x = 0.05) belonging to rhombohedral (R3c) structure show 4A{sub 1} and 7E fundamental Raman modes in the range of 100–650 cm{sup −1} and two-phonon scattering modes such as 2A{sub 4} (longitudinal optical), 2E8 (transverse optical (TO)), and 2E{sub 9} (TO) in the range of 950–1270 cm{sup −1}. Suppression, broadening, and shifting of Raman modes have been observed with further increase in Dy concentration. The fundamental Raman modes of Bi{sub 1−x}Dy{sub x}FeO{sub 3} (x = 0.15) are assigned under orthorhombic (pnma) rather than rhombohedral (R3c) as the Rietveld analysis of X-ray diffraction data predicts a structural transformation for this particular composition. A complete suppression of two phonon modes has been noticed for this composition. An anomaly in the temperature dependent dielectric studies has been observedmore » in all the samples at the vicinity of Neel temperature indicating a magnetic ordering, and an increase in magnetization with increase of Dy concentration in BiFeO{sub 3} is noticed from the room temperature magnetic studies. P–E hysteresis loop studies show a decrease of remnant polarization (P{sub r}) with the increase in Dy concentration and disappearance of hysteresis loop occurs for Bi{sub 1−x}Dy{sub x}FeO{sub 3} (x = 0.15) depicting a transformation from non-centrosymmetric (R3c) to centrosymmetric (Pnma) system.« less
Authors:
;  [1]
  1. Advanced Functional Materials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli 620 015 (India)
Publication Date:
OSTI Identifier:
22304221
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; BISMUTH COMPOUNDS; COPRECIPITATION; CRYSTAL STRUCTURE; DIELECTRIC MATERIALS; DYSPROSIUM ADDITIONS; FERRITES; HYSTERESIS; MAGNETIZATION; NANOPARTICLES; NEEL TEMPERATURE; ORTHORHOMBIC LATTICES; PARTICLE SIZE; POLARIZATION; RAMAN SPECTRA; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TRANSFORMATIONS; TRANSMISSION ELECTRON MICROSCOPY; TRIGONAL LATTICES; X-RAY DIFFRACTION