Absorption of 90° domain walls to oxygen vacancies investigated through internal friction technique

Abstract

We found that 90 • domain walls are absorptive to oxygen vacancies and the absorbing degree was related with the morphology of 90 • domain walls: curved 90 • domain walls are more absorptive to oxygen vacancies compared with straight 90 • domain walls. Therefore, in ferroelectric materials with curved 90 • domain walls, the density of oxygen vacancies diffusing to and subsequently pinning the 180 • domain walls is greatly suppressed, resulting in their excellent fatigue resistance.

Multiferroic Domain Walls in Ferroelectric PbTiO3 with Oxygen Deficiency

“…The trap energy of an oxygen vacancy at the DW is given as E trap = E vf (V O c domain ) – E vf (V O c DW ) = 0.32 eV, which is consistent with previous study . This indicates that the oxygen vacancies are more likely to be trapped at DWs, which results in a high oxygen vacancy concentration at the DW center, as has also been extensively investigated previously. , Experimental observations have also shown a high accumulation of oxygen vacancies near DWs and approximately 90% of total oxygen vacancies can be absorbed by 90° DWs. , Note that the introduction of the oxygen vacancies usually influence the ferroelectric property of the host material. , In the case of DW oxygen vacancy, the induced ferroelectric disturbance is nonlinear and complicated due to its low symmetry (see Supporting Information Figure S2). However, such effect is small (within 3% of bulk value) and only confined around the vacancy site, which will not considerably affect the polarization property of the DW.…”

“…Note also that oxygen vacancies are easily trapped and accumulate at the DW center due to their large trap energy, which results in a high concentration of magnetized vacancies at the DW. Experimental observations have also shown a high concentration of oxygen vacancies at the DW. , As a result, a considerable fraction of a ferroelectric DW is possible to be magnetized. This self-assembling nature of oxygen vacancies and the localized character of emerging spin moments thus turn the DW into a multiferroic atomic layer due to the atomically thin geometry.…”

Thermodynamics of mono- and di-vacancies in barium titanate

“…It is furthermore assumed that oxygen vacancies play a key role in ageing and fatigue of ferroelectric materials by impeding domain wall motion or by acting as local disturbances of the polarization (see e.g., Refs. [15][16][17][18][19]. For this reason, oxygen vacancies and their associates have been intensively studied in experimentally (see e.g., Refs.…”

Aging-induced domain memory in acceptor-doped perovskite ferroelectrics associated with ferroelectric-ferroelectric transition cycle

“…The acceptor dopant produces oxygen vacancies in the system. Such oxygen vacancies can migrate inside the system [24] and intrinsically form in the whole domain volume [18,25,26] a short-range order configuration as a result of their interaction with crystal symmetry during aging. When cooling down from the paraelectric cubic phase, the unaged acceptor-doped ferroelectric sample tends to form a cubic defect symmetry with the configuration of oxygen vacancies randomly distributed around the acceptor dopant (fig.…”