Lead-free piezoelectric system (Na0.5Bi0.5)TiO3-BaTiO3: Equilibrium structures and irreversible structural transformations driven by electric field and mechanical impact


Autoria(s): Garg, Rohini; Rao, Badari Narayana; Senyshyn, Anatoliy; Krishna, PSR.; Ranjan, Rajeev
Data(s)

2013

Resumo

The structure-property correlation in the lead-free piezoelectric (1 - x)(Na0.5Bi0.5)TiO3-(x)BaTiO3 has been systematically investigated in detail as a function of composition (0 < x <= 0.11), temperature, electric field, and mechanical impact by Raman scattering, ferroelectric, piezoelectric measurement, x-ray, and neutron powder diffraction methods. Although x-ray diffraction study revealed three distinct composition ranges characterizing different structural features in the equilibrium state at room temperature: (i) monoclinic (Cc) + rhombohedral (R3c) for the precritical compositions, 0 <= x <= 0.05, (ii) cubiclike for 0.06 <= x <= 0.0675, and (iii) morphotropic phase boundary (MPB) like for 0.07 <= x < 0.10, Raman and neutron powder diffraction studies revealed identical symmetry for the cubiclike and the MPB compositions. The cubiclike structure undergoes irreversible phase separation by electric poling as well as by pure mechanical impact. This cubiclike phase exhibits relaxor ferroelectricity in its equilibrium state. The short coherence length (similar to 50A degrees) of the out-of-phase octahedral tilts does not allow the normal ferroelectric state to develop below the dipolar freezing temperature, forcing the system to remain in a dipolar glass state at room temperature. Electric poling helps the dipolar glass state to transform to a normal ferroelectric state with a concomitant enhancement in the correlation length of the out-of-phase octahedral tilt.

Formato

application/pdf

Identificador

http://eprints.iisc.ernet.in/47041/1/PhysRevB.88.014103.pdf

Garg, Rohini and Rao, Badari Narayana and Senyshyn, Anatoliy and Krishna, PSR. and Ranjan, Rajeev (2013) Lead-free piezoelectric system (Na0.5Bi0.5)TiO3-BaTiO3: Equilibrium structures and irreversible structural transformations driven by electric field and mechanical impact. In: PHYSICAL REVIEW B, 88 (1).

Publicador

AMER PHYSICAL SOC

Relação

http://dx.doi.org/10.1103/PhysRevB.88.014103

http://eprints.iisc.ernet.in/47041/

Palavras-Chave #Materials Engineering (formerly Metallurgy)
Tipo

Journal Article

PeerReviewed