The missing boundary in the phase diagram of PbZr1−xTixO3

Abstract

(PZT) is one of the most important and widely used piezoelectric materials. The study of its local and average structures is of fundamental importance in understanding the origin of its high-performance piezoelectricity. Pair distribution function analysis and Rietveld refinement have been carried out to study both the short-and long-range order in the Zr-rich rhombohedral region of the PZT phase diagram. The nature of the monoclinic phase across the Zr-rich and morphotropic phase boundary area of PZT is clarified. Evidence is found that long-range average rhombohedral and both long-and short-range monoclinic regions coexist at all compositions. In addition, a boundary between a monoclinic (M A ) structure and another monoclinic (M B ) structure has been found. The general advantage of a particular monoclinic distortion (M A ) for high piezoactivity is discussed from a spatial structural model of susceptibility to stress and electric field, which is applicable across the wide field of perovskite materials science.

Effect of off-center ion substitution in morphotropic lead zirconate titanate composition

“…8 The coexistence of tetragonal (space group mm P4 ) and monoclinic (spacegroup Cm ) phases as a result of a first order phase transition between the low temperature monoclinic and high temperature tetragonal phases were identified from x-ray diffraction refinement of pure PbZrxTi1-xO3 ceramics (0.515<x<0.530). (222) Bragg peaks are not expected.…”

Diffused Phase Transition Boosts Thermal Stability of High‐Performance Lead‐Free Piezoelectrics

“…[1] However, a possible toxicity of lead in PZT and PMN-PT has been raising intense health and environmental concerns; thus, the last decade has witnessed the surging dedication to viable lead-free alternatives. [2][3][4][5] Resembling the principle characteristics of MPB, [4][5][6][7][8][9][10] polymorphic phase transition (PPT) boundary has also been extensively pursued. [2,11,12] Unfortunately, contrary to the nearly vertical MPB in the well-known PZT and PMN-PT systems, [1] the PPT in lead-free piezoelectrics is always tilted, resulting in unavoidable thermally unstable electromechanical properties.…”

Elastic and anelastic relaxation behaviour of perovskite multiferroics I: PbZr0.53Ti0.47O3 (PZT)–PbFe0.5Nb0.5O3 (PFN)

“…monoclinic or tetragonal ? monoclinic structures [50,51,71]. Coexistence of tetragonal and rhombohedral phases near the MPB has been reported for samples doped with 5-6 % Fe 3?…”

“…This phase boundary extrapolates to the location of the MPB at *160 K, *50 % PT [38,44,49], though extrapolation to *0 K at *50 % PT has also been shown in some phase diagrams [50,51]. Diffraction and dielectric evidence for a tilting transition at *210 K in Pb(Zr 0.52 Ti 0.48 )O 3 [52,53] is consistent with the topology given by Cordero et al [44] and calculated from first principles by Kornev et al [54].…”