A Hydrothermally Deposited Epitaxial PbTiO₃ Thin Film on SrRuO₃ Bottom Electrode for the Ferroelectric Ultra-High Density Storage Medium

Abstract

A lead titanate epitaxial thin film is one of the important ferroelectric films and lattice matching with strontium titanate is preferable. However, it was thought to be difficult to obtain high insulation property and very few superior hysteresis curves were measured with lead titanate. The hydrothermal method can avoid a lead vacancy and residual strain at the boundary of the substrate due to low reaction temperature of 150• C. Using strontium ruthenium oxide bottom electrode on strontium titanate, the lead titanate thin film was successfully deposited by the hydrothermal method. The single crystal-like DE hysteresis curve showed a remanent polarization of 96.5 µC/cm 2 . The domain direction was controlled by an applied electric field using a metal coated AFM cantilever probe and the domain pattern was observed by scanning nonlinear dielectric microscopy (SNDM). Minimum dot radius of inverted domain was 12 nm corresponding to data storage density of 1 Tbit/inch 2 .

Crystal structure, ferroelectric and piezoelectric properties of epitaxial (1−x)(Bi0.5Na0.5)TiO3–x(Bi0.5K0.5)TiO3 films grown by hydrothermal method

“…In-plane and out-of-plane lattice parameters of ( 1 out-of-plane lattice parameters, (a and c, respectively), against x in (1−x)BNT-xBKT films in this work together with the reported lattice parameters of (1−x)BNT-xBKT ceramics prepared by a conventional sintering technique. 22) The a lattice parameter of (1−x)BNT-xBKT ceramics increases slightly as x increases, while that of (1−x)BNT-xBKT films is almost a constant, which is well matched with the lattice parameter of SrRuO 3 films and SrTiO 3 (3.905 Å) 37) as can be seen from the RSMs shown in Fig. S2, indicating that the films are strongly clamped by SrRuO 3 films and SrTiO 3 substrates and exhibit coherent epitaxy.…”

Chemical Solution Deposition of Epitaxial Metal‐Oxide Nanocomposite Thin Films

“…Thicker films are favorable for applications in piezoelectric microacuators and microsensors [46] . In the hydrothermal process, polarization is aligned automatically to achieve a 3D deposition [47] . The reaction temperature, pressure, and solution pH value are all important factors in controlling film properties, like composition and thickness.…”

Deposition of PbTiO3 films on Pt/Si substrates using pulsed laser deposition

“…It may be noted that Morita et al have reported P r up to 96.5 C/cm 2 with a coercive field ∼290 kV/cm for highly epitaxial (0 0 1) PTO films grown on a SrRuO 3 /SrTiO 3 substrate by a hydrothermal process. 33 As PbTiO 3 doesn't exhibit the polarization rotation noted in morphotropic phase boundary PZT, we can estimate a value of P r in the (1 0 0) direction, by a simple projection onto the [0 0 1] axis resulting in P r (0 0 1) ≈ 73 C/cm 2 , approximately 25% less than Morita's value.…”