Study of domains and domain walls in ferroelastic BiVO4

Abstract

The domain structure of pure ferroelastic BiVO, has been studied by TEM and electron diffraction. Parallel domain walls w' have been imaged in dark field conditions as alternating black and white lines. Angles between domain walls, between domain walls and the [loo] axis and the rotation angle between the (hkO) reciprocal planes of two adjacent ferroelastic domains were measured and are in good agreement with calculated values. The multiple splitting of the hkO diffraction spots when both w' walls are present simultaneously is discussed.

BiVO4based highkmicrowave dielectric materials: a review

“…[39][40][41][42][43]51 Natural pucherite BiVO4 transforms to a pure scheelite monoclinic phase when heated above 500 o C and cooled room temperature in a sealed Pt tube (Roth and Waring 4,52 ) but has never been synthesized in the laboratory. From 420 to 500 o C, pucherite BiVO4 coexists with the tetragonal scheelite phase and becomes single phase only above 500 o C. 2,3,37,54 Scheelite tetragonal BiVO4 is thus considered metastable and readily transforms to the monoclinic phase in acid solutions. 53 The scheelite monoclinic to tetragonal BiVO4 phase transition is second order at 255 o C accompanied by recovery of the distorted BiO8 dodecahedra and VO4 tetrahedra to regular polyhedral.…”

“…This transition may also be induced by external pressure. 53,54 The phase transition sequence of the four polymorphs of BiVO4 is presented in Fig. 5.…”

Structure of Thin Pseudo-90° Domain Walls in BaTiO3

“…It is known that in ferroelastics [1,2] and multiaxial ferroelectrics [3,4] the rotation of ferroelectric phase crystallographic axes with respect to paraphase is observed with increase of spontaneous deformation. This leads to the formation of near-oriented states (sub-oriented) and to the increase of the number of structural and electric domains types.…”

Temperature dependence of domain walls in LaNbO4and their relation to the spontaneous strain

“…(Ishibashi, 1979;Wainer et al, 1981;David and Wood, 1983;Boulesteix, 1984). These rotations were described in detail by David and Wood (1983, Section 2.3) for the 4/mF2/m ferroelastic species where it was shown, in particular, that full strain compatibility could only be achieved by a set of parallel walls.…”