Structural, microstructural and thermal properties of lead-free bismuth–sodium–barium–titanate piezoceramics synthesized by mechanical alloying

Journal Article · Fri Feb 15 00:00:00 EST 2013 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2012.11.008· OSTI ID:22215817

Amini, Rasool ^[1]; Ghazanfari, Mohammad Reza; Alizadeh, Morteza; Ardakani, Hamed Ahmadi ^[1]; Ghaffari, Mohammad ^[2]

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1. Department of Materials Science and Engineering, Shiraz University of Technology, 71557-13876 Shiraz (Iran, Islamic Republic of)
2. Department of Electrical and Electronics Engineering, UNAM—National Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey)

Graphical abstract: Mechano-synthesis of lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.94}Ba{sub 0.06}TiO{sub 3} piezoceramics with nanocrystalline/amorphous structure and homogeneous composition: partial transformation of constituents to BNBT, BNT and pyrochlore, amorphous phase formation, mechano-crystallization of the amorphous, pyrochlore-to-perovskite BNBT phase transformation during the process. Display Omitted Highlights: ► Perovskite BNBT powders with homogeneous composition were synthesized by MA. ► Partial transformation of constituents to BNBT, BNT and pyrochlore occurred by MA. ► Formation of an amorphous phase and afterwards its crystallization occurred by MA. ► Pyrochlore-to-perovskite BNBT phase transformation occurred after prolong milling. ► Polymorphic transformations of TiO{sub 2} act as the main alloying impediment during MA. -- Abstract: Bismuth–sodium–barium–titanate piezoceramics with a composition of (Bi{sub 0.5}Na{sub 0.5}){sub 0.94}Ba{sub 0.06}TiO{sub 3} (BNBT) were prepared by mechanical alloying (MA). Structural analysis and phase identification were performed by X-ray diffraction (XRD). Microstructural studies and chemical composition homogeneity were performed by scanning electron microscope (SEM) coupled with energy dispersive X-ray analysis (EDX). Furthermore, thermal properties of the as-milled powders were evaluated by thermogravimetry/differential thermal analysis (TG/DTA). During the initial milling, the constituents were transformed to the perovskite, pyrochlore, and BNT phases; in addition, partial amorphization of the structure appeared during the milling cycle. As MA progressed, transformation of pyrochlore-to-perovskite and crystallization of the amorphous phase occurred and also, the BNBT phase was significantly developed. It was found that the MA process has the ability to synthesize the BNBT powders with a submicron particle size, regular morphology, and uniform elemental distribution.

• OSTI ID: 22215817
• Journal Information: Materials Research Bulletin, Vol. 48, Issue 2; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
CERAMICS
CHEMICAL COMPOSITION
CRYSTALLIZATION
CRYSTALS
DIFFERENTIAL THERMAL ANALYSIS
MICROSTRUCTURE
NANOSTRUCTURES
PARTICLE SIZE
PEROVSKITE
POWDERS
PYROCHLORE
SCANNING ELECTRON MICROSCOPY
SYNTHESIS
THERMAL GRAVIMETRIC ANALYSIS
THERMODYNAMIC PROPERTIES
X RADIATION
X-RAY DIFFRACTION