Stress-induced phase transition in ferroelectric domain walls of BaTiO₃

Abstract

The seminal paper by Zhirnov (1958 Zh. Eksp. Teor. Fiz. 35 1175-80) explained why the structure of domain walls in ferroelectrics and ferromagnets is drastically different. Here we show that the antiparallel ferroelectric walls in rhombohedral ferroelectric BaTiO(3) can be switched between the Ising-like state (typical for ferroelectrics) and a Bloch-like state (unusual for ferroelectric walls but typical for magnetic ones). Phase-field simulations using a Ginzburg-Landau-Devonshire model suggest that this symmetry-breaking transition can be induced by a compressive epitaxial stress. The strain-tunable chiral properties of these domain walls promise a range of novel phenomena in epitaxial ferroelectric thin films.

Ferroelectric Transitions at Ferroelectric Domain Walls Found from First Principles

“…One might describe the found transition as a change in the DW character, from Bloch to Ising, upon heating; in fact, some authors have discussed similar effects in these terms [20,22]. However, we think that our result is better described as a proper FE phase transition confined to the DW, to emphasize that it results in a switchable DW polarization.…”

“…In fact, we still lack a detailed structural and dynamical picture of the DWs, and in many cases we can only speculate about the structure-property relationships at work within them. Hence, there is a pressing need for predictive theoretical studies tackling the DWs at an atomistic level and at the relevant conditions of temperature, etc.The DW structure, and even the possible occurrence of DW-confined ferroic orders, have been discussed theoretically for decades, usually in the framework of continuum Ginzburg-Landau or phenomenological model theories [12][13][14][15][16][17][18][19][20][21][22]. Materials with competing structural instabilities have been a focus of attention, a good example being perovskite SrTiO 3 (STO).…”

Bistability of ferroelectric domain walls: Morphotropic boundary and strain effects

“…[2][3][4] The intention to create nanodevices on the basis of domain walls motivates further fundamental research of their internal structures. Of special interest are theoretical results predicting bistable domain walls 5,6 where information may be potentially stored. This type of wall may exist between two oppositely poled domains (180…”

“…However, at some material parameters an additional polarization component P 2 may arise, breaking the centrosymmetry of the wall. 6 The resulting two-component solution for the polarization is referred to as Bloch wall; its profile is shown in Figs. 1(b) and 1(c).…”

“…This feature makes Bloch walls interesting objects from the point of view of dense memory applications. To the best of our knowledge the only material where Bloch walls are predicted is the rhombohedral phase of BaTiO 3 , [5][6][7][8] and this is done by numerical simulations, based on LandauGinsburg-Devonshire (LGD) theory and ab initio calculations. However, such domain walls may have limited applications because of difficulties, associated with cryogenic temperatures needed to obtain this phase in the material.…”