Structure and phase transitions of lead zirconate hafnate solid solutions

Crystallographic and optical study of PbHfO3 crystals

“…These are in agreement, confirming that the antiferroelectric orthorhombic A 1 structure has space group Pbam. The intermediate phase has not been reliably determined and it has been suggested that it is orthorhombic (Leont'ev et al, 1984), rhombohedral (Dernier & Remeika, 1975) or tetragonal (Shirane & Pepinsky, 1953;Fujishita & Ishikawa, 2002) or is initially orthorhombic from 433 to 453 K and tetragonal between 463 and 493 K (Kabirov et al, 2011).…”

“…A range of techniques have been utilized to determine the temperature of each phase transition: these have included dielectric spectroscopy (Shirane & Pepinsky, 1953;Roleder et al, 2000;Kabirov et al, 2011), Raman spectroscopy (Sharma et al, 1994), differential scanning calorimetry (Yoshida et al, 2009), powder X-ray diffraction (Kwapulinski et al, 1994) and powder neutron diffraction (Fujishita et al, 2008). These measurements have suggested that the A 1 -to-A 2 phase transition occurs between 433 and 443 K with thermal hysteresis; the phase change is between 5 and 7 K lower on cooling.…”

Investigation on antiferroelectricity of Pb0.97La0.02(Hf1−xTix)O3ceramics with low Ti content (0 ≤ x ≤ 0.1)

“…When x ≤ 0.04, these superlattice reflections can be assigned to G ± 1/4(1 1 0) satellite reflections (G denotes parent reflections) and are caused by the antiparallel Pb cation displacements (AFE) along the cubic perovskite (1−10) direction, 32 which is in good agreement with the AFE distortion observed in the PbHfO 3 (AFE O structure, space group: Pbam). 20,21,23 However, the superlattice reflections symbolizing AFE disappeared when x ≥ 0.06, instead of the present extra satellite reflections close to (2 1 1) can be found, indicating a change of crystallographic structure. Further looking into this the origin of this satellite reflection, it can be assigned to INC modulation, according to the previous publication.…”

“…19,20 Shirane et al depicted the AFE(II) phase as a tetragonal structure in the temperature range of 163-215 • C. 17 Kabirov et al presented the phase structure of PHO ceramics as orthorhombic with Pbam (20-150 • C), A2mm space group (160-180 • C), and tetragonal with P4mm space group (190-220 • C). 21 In more recent work by Bosak et al, the AFE(II) phase is orthorhombic with Imma space group. 19 In addition, there are few results at high electric field in early time due to the high phase transition field of PHO-based AFEs.…”

“…Kabirov et al. presented the phase structure of PHO ceramics as orthorhombic with Pbam (20–150°C), A 2 mm space group (160–180°C), and tetragonal with P 4 mm space group (190–220°C) 21 . In more recent work by Bosak et al., the AFE(II) phase is orthorhombic with Imma space group 19 …”