Phase transitions and physical properties of Pb₈V₂O₁₃single crystals

Phase transitions in Pb8O5(XO4)2 (X = As and V) compounds

“…7(b). At this temperature, Type a domains vanish, which is in good agreement with the results of Baggio et al [12,13] These authors measured the angle between Type a domains, showing that it continuously vanishes on heating following a power law behavior characterizing a second-order phase transition. Type b domains are clearly observed up to 573K, as shown in Fig.…”

“…4(b) shows the existence of a first-order phase transition at around 540 K. The lack of precision in the determination of this transition temperature evidences the ferroelasticity of PbVO. As also observed by Baggio et al [12] the endothermic peak associated with this first-order phase transformation is characterized by several sharp anomalies corresponding to the transition temperature of individual crystals. As the pattern of the ferroelastic domains in a single crystal is determined by their size and thermal history, the same parameters also determine the energy involved in the formation of the domain walls.…”

“…The ferroelastic character of PbVO is discussed in Refs [5,6,12,13]. Based on polarized microscopy and thermal analwileyonlinelibrary.com/journal/jrs ysis, two phase transitions were identified.…”

“…On the other hand, the roomtemperature phase of PbVO is controversial. von Hondenberg [8] reported that the room temperature phase of PbVO is monoclinic with possible space groups C2, Cm or C2/m and Z = 8, while Kiosse et al [11] and Baggio et al [12,13] reported that PbVO also exhibits a monoclinic structure with possible space groups P21/m (nonpolar) or P21 (polar) with Z = 8.…”