Effect of stress induced monoclinic to tetragonal phase transformation in the multiferroic (1-x)BiFeO3-xPbTiO3 system on the width of the morphotropic phase boundary and the tetragonality

Lead-based piezoelectric ceramics have excellent piezoelectric properties with the compositions near the rhombohedral-tetragonal morphotropic phase boundary (MPB)[1,2]. In these materials, the dielectric and piezoelectric properties show the maximal values at MPB. For lead-free piezoelectric ceramics, finding the MPB area is a promising way to improve their properties. In this paper, the (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3 lead-free piezoelectric ceramics were prepared by solid-state reaction method, and their piezoelectric properties and dielectric properties were investigated. With the increase of KNLN content, the crystal structure changed from rombohedral phase to tetragonal phase, thus existed a MPB[3,4] between rombohedral and tetragonal phase. At room temperature, the specimen with the composition at MPB (x=0.93, y=0.01) shows the optimal piezoelectric properties (d33=225pC/N and kp=45%), which indicates that this material is a potential lead-free piezoceramic.

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Large nonlinear electrostrain and piezoelectric response in nonergodic (Na,K)0.5Bi0.5TiO3 : Synergy of structural disorder and tetragonal phase in proximity to a morphotropic phase boundary

Physical Review Materials ◽

10.1103/physrevmaterials.5.064414 ◽

2021 ◽

Vol 5 (6) ◽

Author(s):

Gobinda Das Adhikary ◽

Vivek Dwij ◽

Anatoliy Senyshyn ◽

Vasant Sathe ◽

Rajeev Ranjan

Keyword(s):

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Tetragonal Phase ◽

Structural Disorder ◽

Piezoelectric Response

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Polar-Toroidal Phase Transformation in Inhomogeneous Nanoscale Ferroelectric Systems: A Novel Strategy for the Design of Energy Conversion Nanodevices

MRS Advances ◽

10.1557/adv.2017.316 ◽

2017 ◽

Vol 2 (56) ◽

pp. 3427-3432

Author(s):

Weijin Chen ◽

Shuai Yuan ◽

Ye Ji ◽

Gelei Jiang ◽

Jian Shao ◽

...

Keyword(s):

Phase Transformation ◽

Energy Conversion ◽

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Large Change ◽

Polarization Field ◽

Phase Boundaries ◽

Thermal Fields ◽

Novel Strategy ◽

Complex Polarization

ABSTRACTThe ordering of polarization field of inhomogeneous ferroelectric systems were investigated. We found that these systems exhibit rather complex polarization ordering behaviors with the coexistence of polar and toroidal ordering, and particularly, a novel and tunable polar-toroidal phase transformation under external mechanical, electrical or thermal fields. Accompanying with this polar-toroidal phase transformation, there is a large change of polarization and strain. As a result, large eletromechanical and thermomechanical performance can be achieved in these systems. The polar/toroidal phase boundaries can be regarded a new kind of morphotropic phase boundary (MPB). The polar-toroidal phase transformation in nanoscale ferroelectric systems should provide us a novel strategy to develop energy conversion nanodevices.

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Dielectric properties of Pb(Zn1/3Nb2/3)O3–PbZrO3–PbTiO3 system in the rhombohedral region near the morphotropic phase boundary

Journal of Materials Research ◽

10.1557/jmr.2000.0393 ◽

2000 ◽

Vol 15 (12) ◽

pp. 2745-2749 ◽

Cited By ~ 13

Author(s):

X. P. Jiang ◽

J. W. Fang ◽

H. R. Zeng ◽

G. R. Li ◽

D. R. Chen ◽

...

Keyword(s):

Phase Transition ◽

Phase Boundary ◽

Morphotropic Phase Boundary ◽

Tetragonal Phase ◽

Rhombohedral Phase ◽

Dissipation Factor ◽

Phase Region ◽

X Ray Diffraction ◽

Tetragonal Phase Transition ◽

Diffuse Phase

A diffuse phase transition for Pb(Zn1/3Nb2/3)O3–PbZrO3–PbTiO3 (PZN-PZ-PT) system in the rhombohedral region near the rhombohedral/tetragonal morphotropic phase boundary (MPB) is reported in this paper. A thermal-driven macrodomain– microdomain switching was revealed and confirmed for compositions close to the MPB in the rhombohedral region after poling. Morever, the transition from rhombohedral phase to tetragonal phase was first revealed in the curves of dielectric permittivity (or dissipation factor) versus temperature. This rhombohedral–tetragonal phase transition resulted from the MPB bending toward the rhombohedral phase region and was confirmed by high-temperature x-ray diffraction.

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Morphotropic Phase Boundary in the Nanocrystalline PbZrxTi1-xO3 System

MRS Proceedings ◽

10.1557/proc-452-857 ◽

1996 ◽

Vol 452 ◽

Author(s):

R. S. Katiyar ◽

J. F. Meng

Keyword(s):

Grain Size ◽

Phase Transformation ◽

Phase Boundary ◽

Raman Spectra ◽

Morphotropic Phase Boundary ◽

Size Dependence ◽

Phonon Mode ◽

Ferroelectric Phase ◽

Soft Mode ◽

Bulk Materials

AbstractMicro Raman spectra for PbZrxTi1-xO3 (PZT) with a grain size of 60 nm have been recorded. The results show that the lowest E(TO) phonon mode of PbTiO3 (soft mode) displays a decrease in frequency and increase in linewidth with increasing Zr concentration. A discontinuous behavior of the phonon energy of the soft mode occurs at x=0.4 and it can be attributed to a phase transformation from the tetragonal ferroelectric to rhombohedral ferroelectric phase in PZT. The coupling between the soft mode and an additional impurity mode, has been observed, which plays an important role in the phase transformation. A lowest phonon mode at 10 cm−1 is detected and it is found to exhibit an increase in intensity for x above 0.2. The grain size dependence of the mode seems to be associated with the effect of grain size on the microstructure in PZT. The mechanism of grain size - induced new morphotropic phase boundary, which is lower than that of the corresponding bulk materials, is discussed.

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