Please use this identifier to cite or link to this item:
Title: Phase formation in the (1- y )BiFeO 3 - y BiScO 3 system under ambient and high pressure
Author: Salak, A. N.
Khalyavin, D. D.
Pushkarev, A. V.
Radyush, Yu. V.
Olekhnovich, N. M.
Shilin, A. D.
Rubanik, V. V.
Keywords: Metastable phase
High-pressure synthesis
Issue Date: 3-Jan-2017
Publisher: Elsevier
Abstract: Formation and thermal stability of perovskite phases in the BiFe1-yScyO3 system (0≤y≤0.70) were studied. When the iron-to-scandium substitution rate does not exceed about 15 at%, the single-phase perovskite ceramics with the rhombohedral R3c symmetry (as that of the parent compound, BiFeO3) can be prepared from the stoichiometric mixture of the respective oxides at ambient pressure. Thermal treatment of the oxide mixtures with a higher content of scandium results in formation of two main phases, namely a BiFeO3-like R3c phase and a cubic (I23) sillenite-type phase based on γ-Bi2O3. Single-phase perovskite ceramics of the BiFe1-yScyO3 composition were synthesized under high pressure from the thermally treated oxide mixtures. When y is between 0 and 0.25 the high-pressure prepared phase is the rhombohedral R3c with the √2ap×√2ap×2√3ap superstructure (ap ~ 4 Å is the pseudocubic perovskite unit-cell parameter). The orthorhombic Pnma phase (√2ap×4ap×2√2ap) was obtained in the range of 0.30≤y≤0.60, while the monoclinic C2/c phase (√6ap×√2ap×√6ap) is formed when y=0.70. The normalized unit-cell volume drops at the crossover from the rhombohedral to the orthorhombic composition range. The perovskite BiFe1-yScyO3 phases prepared under high pressure are metastable regardless of their symmetry. At ambient pressure, the phases with the compositions in the ranges of 0.20≤y≤0.25, 0.30≤y<0.50 and 0.50≤y≤0.70 start to decompose above 970, 920 and 870 K, respectively
Peer review: yes
DOI: 10.1016/j.jssc.2016.12.029
ISSN: 0022-4596
Appears in Collections:CICECO - Artigos

Files in This Item:
File Description SizeFormat 
Salak_JSSC-2017.pdf1.23 MBAdobe PDFView/Open

Formato BibTex MendeleyEndnote Degois 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.