Ferroelectric Thin Films of Bismuth‐Containing Layered Perovskites: Part I, Bi₄Ti₃O₁₂

Abstract

Ferroelectric thin films of bismuth-containing layered perovskite Bi 4 Ti 3 O 12 have been fabricated by a metalorganic decomposition (MOD) method. Crack-free and crystalline films of ∼5000 Å thickness have been deposited on Pt/Ti/SiO 2 /Si substrates. Different heat treatments have been studied to investigate the nucleation and growth of perovskite Bi 4 Ti 3 O 12 crystallites. If the same composition and final annealing temperature are used, films with different orientations are obtained by different heating schedules. These films show a large anisotropy in ferroelectric properties. Theoretical considerations are presented to suggest that nucleation control is responsible for texture and grain-size evolution. Moreover, the origin of the ferroelectric anisotropy is rooted in the two-dimensional nature of layered polarization.

Sub‐Picosecond Processes of Ferroelectric Domain Switching from Field and Temperature Experiments

“…[1] This time is limited by the speeds of thermally fluctuating domain nucleation and subsequent growth. Ultimately, polarization reversal may be limited by optical phonon frequencies with reciprocal times of τ 0 ≈ 10 −13 s. [2][3][4][5][6] The terahertz emission occurring under laser illumination suggests that depolarization occurs within 1-2 ps in ABO 3 ferroelectric oxides. [7] For an ultrathin film thickness comparable to the critical size (h) of the reverse nucleus above which they grow rapidly, domain nucleation transits into a continuous switching mechanism under an ultrahigh intrinsic coercive field (E 0 ).…”

Enhanced Electrical Properties of 3-0 Type Na0.5Bi2.5Nb2O9-BaTiO3 Composite High-Temperature Piezoelectric Ceramics

“…The strongest diffraction peak is (115), which is consistent with the (112m+1) highest diffraction peak in BLSFs. 19 There are no obviously additional diffraction peaks appearing after the introduction of BaTiO 3 into NBN in this work. Moreover, it's noted that the (0010) diffraction peaks shift towards to lower 2θ angles as shown in Figure 2b.…”

Magnetodielectric effect of Bi6Fe2Ti3O18film under an ultra-low magnetic field

“…Ultimately, the multilayer film were subject to furnace at 650-750℃ for 60 minutes so as to grow grain sizes [16]. Before electric characterizations, each sample was also needed to be deposited a thin platinum layer (30-100nm) as top electrode via mask technology, where the round electrode areas were confined in the range of 0.04-1mm 2 .…”

“…The spinning parameters were set at 4000rpm for 30s. Wet films were subsequently placed onto hot plates with temperatures at 160-180℃ for 1 minute to vaporize solvent and other volatiles, and at 400-500℃ for 10 minutes to nucleate Bi-layered structure, respectively [16].…”