Direct observation of domain kinetics in rhombohedral PMN-28PT single crystals during polarization reversal

Abstract

Relaxor-based ferroelectric crystals of lead magnesium niobate-lead titanate (PMN-PT) are attracting great attention due to their prominent piezoelectric properties. Moreover, an enhancement of the integral properties requires the deep understanding of domain kinetics and domain structure evolution for application of the domain engineering techniques in relaxor-PT materials. Here, we demonstrate the results of studying the domain structure evolution by direct optical imaging during polarization reversal in [111]-oriented rhombohedral PMN-PT single crystals. Three domain types involved in the switching process have been revealed. The following consequent stages of the domain structure evolution have been separated: (I) nucleation and growth of a↑-domains and 2a-CDW and (II) nucleation and growth of c↓-domains. The undesirable effect of the partial backswitching during the electric field decrease was attributed to the clamped switching conditions.

Dense ferroelectric-ferroelastic domain structures in rhombohedral PMN-28PT single crystals

“…The typical optical images of the dense domain structure (DDS) evolution obtained at the stage of nucleation, growth, and intersection of a"-domains 16 (i) and 1(j). It was proposed that the intersection of a"-domains led to the formation of the DDS consisting of needle-like domains with charged walls (2a-CDW).…”

“…It was proposed that the intersection of a"-domains led to the formation of the DDS consisting of needle-like domains with charged walls (2a-CDW). 16 During the rise of the field, the nucleation and elongation of the DDS [Fig. 1(g) and 1(h)] impeded an optical observation of the forming domain pattern due to the light dissipation.…”

“…[12][13][14][15] Earlier, we studied the domain structure evolution in rhombohedral [111]-oriented PMN-PT single crystals during polarization reversal. 16 We used the direct optical observation of the domain structure during polarization reversal and proposed the following domain structure evolution stages: (1) nucleation and growth of a-domains and domains with charged domain walls at the intersection of two a-domains (2a-CDW) representing the creation of the so-called DDS and (2) consequent growth of c-domains. It is worth noting that the term "dense" does not mean "extremely dense" but is introduced in order to separate and mark the domain structure types.…”

“…27 The unipolar trapezoidal electric field pulse was used for the polarization reversal. 16 The pulse amplitude was 275 V/mm, the pulse duration was 1.5 s, and the rise and fall time was 100 ms. The sample was pre-poled before polarization reversal experiments by the application of a trapezoidal field pulse with an amplitude of 300 V/mm and a duration of 3 s. This procedure allows obtaining the domain structure with the preferred orientation of c-domains (here, c"-domains) and small amount of a"-domains.…”

Identification of a coherent twin relationship from high-resolution reciprocal-space maps

“…These techniques are based on e.g. optical and birefringence microscopy (Ushakov et al, 2019;Gorfman et al, 2012), piezo response-force (PFM) (Gruverman et al, 2019) microscopies or X-ray topography (Yamada et al, 1966). Each of these said techniques contains some disadvantages, which limit the completeness and efficiency of the characterization.…”