High-Temperature Phase Transitions in PbZrO₃

Abstract

A high‐temperature X‐ray diffraction study of a high‐purity PbZrO3 specimen at 25° to 236°C is reported. The symmetry of the perovskite sub‐cell of PbZrO3 was determined unambiguously by observing the splitting of the line groups N= 12 and N= 16 when the diffraction pattern was indexed on the basis of the perovskite cell being a unit cell for the structure. Diffractometer studies were conducted of the N= 12 line group using Fe Kα radiation and of the N= 16 line group using Cu Kα radiation. The ferroelectric phase of PbZrO3 possessed a rhombohedral sub‐cell with the angle α being acute. Stable two‐phase mixtures and considerable thermal hysteresis were observed at the antiferroelectric α ferroelectric transition temperature. A very weak “extra” diffraction line was observed in the diffraction patterns of the ferroelectric and paraelectric phases, indicating that the unit cells of these structures may be multiples of the perovskite subcell.

Strain on ferroelectric thin films

“…Nevertheless its dielectric [33][34][35][36], piezoelectric [37] and structural [38][39][40] properties as well as the ones with \10% of PbTiO 3 [9] were studied as early as the 50s. The existence of a ferroelectric rhombohedral phase on a narrow range of temperature (503-506 K upon heating and 505-500 K upon cooling) between the paraand antiferroelectric phases was confirmed later [41][42][43] and a detailed study of the phase transitions by combined X-ray diffraction, dielectric and birefringence measurements determined the displacement of lead atoms (described by Kittel's theory of antiferroelectricity [44]) as well as the oxygen octahedra rotation [45]. The possibility to induce a ferroelectric phase thanks to (high) electric fields in the nominally antiferroelectric phase of PbZrO 3 was reported and the electric field-temperature phase diagram for PbZrO 3 established by Fesenko et al [46].…”

Epitaxial strain stabilization of a ferroelectric phase in PbZrO3thin films

“…The manifestation of the rhombohedral phase in PZO has been reported earlier in single crystals and high-purity ceramics of the material within a narrow range of temperature near T C . [20][21][22][23] In case of thin films, PZO is likely to grow in the cubic phase at the deposition temperature (T d ∼ 575…”

“…19 Manifestation of ferroelectricity in high-purity ceramics and single crystals of PZO was also observed in a narrow temperature range near the T C , and in these cases the AFE O to paraelectric-cubic (PE C ) phase transition was found to be associated with an intermediate FE R phase. [20][21][22][23] Room-temperature ferroelectricity in PZO was demonstrated by Ayyub et al 24 for thin films below a critical thickness of ∼500 nm fabricated on p-type Si substrates and was explained in terms of the effective built in electric field at the PZO and Si interface. Various research groups reported that such size-dependent physical properties in different materials are associated with a structural phase transition, which can be achieved by stressing their epitaxial thin films through effective misfit.…”

Effect of Excess Lead Oxide on Phase Transitions and Physical Properties of Provskite Lead Barium Zirconate Ceramics

“…The measurements of the length of a specimen at various temperatures of solid materials are usually applied for the determination of the kinetics of phase transformation of PZ Downloaded by [University of Lethbridge] at 20:32 26 June 2016 Table 1 Intensity ratio of 004/240 peak, lattice parameter, unit cell volume, density and transition temperature of PBZ10 ceramics with different amounts of excess PbO [12,13]. The dilatometric thermal expansion of PBZ10 with excess PbO on heating cycle is plotted in Fig.…”