Grain size induced monoclinic (Cm) to rhombohedral (R3c) transformation in sodium potassium bismuth titanate ceramics

Journal Article · 01 August 2017 · Scripta Materialia

DOI: https://doi.org/10.1016/j.scriptamat.2017.07.022 · OSTI ID:1459948

Gajendra Babu, M. Veera ^[1]; Bagyalakshmi, B. ^[1]; Padiyan, D. Pathinettam ^[1]; Ren, Y. ^[2]; Sundarakannan, B. ^[1]

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1. Manonmaniam Sundaranar Univ., Tirunelveli (India)
2. Argonne National Lab. (ANL), Argonne, IL (United States)

Here, grain size effect on structure, remnant polarization and piezoelectric constant of lead-free Na_0.4K_0.1Bi_0.5TiO₃ ceramics with grain sizes of 0.58, 0.85, 1.19 and 1.83 pm was investigated. Synchrotron X-ray diffraction in combination with Rietveld refinement was used to examine the structural changes. We have reported an existence of monoclinic (Cm) phase at room temperature and discussed the grain size (1.83 → 0.58 μm) induced structural transformation (Cm → R3c) through both intrinsic polarization rotation and adaptive phase theory. Polarization vector in the (11¯0)_pc monoclinic plane rotates towards [111]_pc with the reduction of grain size. Better domain alignment and large polar variants results enhanced remnant polarization and piezoelectric constant in 1.83 μm sample.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: University Grants Commission (UGC) of India; USDOE
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1459948
• Journal Information: Scripta Materialia, Vol. 141, Issue C; ISSN 1359-6462
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English