Hydrothermally synthesized BaTiO3 textured in a strong magnetic field

Abstract

Hydrothermally synthesized BaTiO 3 was colloidally consolidated by slip casting and by electrophoretic deposition in a high strength magnetic field of 17.4 T. Textured BaTiO 3 was successfully prepared by both processing techniques, with the {001} plane aligning normal to the direction of the magnetic field. The initial alignment in the green powder compact was preserved and enhanced after sintering from 1400 1C to 1500 1C. The sintering temperature hardly influenced the degree of texture in slip cast samples but did influence the grain size of all BaTiO 3 ceramics and the degree of texture in the electrophoretically deposited samples. The BaTiO 3 ceramics processed in the strong magnetic field showed crystallographic texture but not morphological, so the microstructure did not show any anisotropy. The highest Lotgering factor (0.85) was measured for the ceramics made by electrophoretic deposition and sintered at 1500 1C.

Texturing of hydrothermally synthesized BaTiO3 in a strong magnetic field by slip casting

“…Here, it was observed that sintering at 1500°C can improve texture of . Vriami et al [4] also reported an improvement of the orientation factor for (prepared by the same synthesis route as described in 2.1 and 2.2) aligned by electrophoretic deposition in a 17.4 vertical magnet and sintered at 1500°C. The slip casted sample showed a maximum in the orientation factor at 1450°C and a mild decrease at 1500°C.…”

“…Texturing of ceramic materials by colloidal processing is one of these techniques. Colloidal processing has been extensively investigated for net shaping methods such as gel casting [1][2][3], electrophoretic deposition [4,5] and slip casting [4,[6][7][8][9]. Controlled conditions of the starting powder, slurry preparation, organic additive removal and sintering resulted in high-quality dense ceramic materials for industrial, medical and commercial use.…”

“…In fact, very few literature is available on textured perovskite ceramics in general and barium titanate in specific. [1,[4][5][6] The available literature mainly reports on [111] & [101]-or [101]-textured . [1,5] Publications on textured are limited and reports of highly textured are even scarcer.…”

“…However, after polishing of the as-sintered slip casts the ceramics were reported to be randomly oriented. Vriami et al [4] reported the texture of hydrothermally synthesized in a very strong magnetic field of 17.4 T by slip casting with an orientation factor of 0.67 for samples sintered at 1450°C. The ceramics were reported to have a fiber texture with the <001> fiber axis aligning parallel to the direction of the magnetic field.…”

In-situ Transmittance Measurement of Polarization and Dielectric Relaxation Behaviors of LiNbO3 Ferroelectric Nanocrystal in Polycarbonate Matrix

“…Through the transmittance measurement, we know that the LiNbO 3 ferroelectric nanocrystals align after poling, while the preferential orientation of LiNbO 3 nanocrystals is not very clear. For ferroelectric nanocrystals/polymer system, the nanocrystals will be aligned to the most stable state with lowest energy under external electric field [17]. For LiNbO 3 nanocrystals, the spontaneous polarization pointing is along [001] direction, which means it's the most susceptible direction under external electric field [18].…”