Papers by Author: Keisuke Satoh

Abstract: Lanthanum-modified lead zirconate titanate and lead zirconate titanate epitaxial films with (100) and (111) orientations were grown respectively on (100) and (111) niobium, lending conductivity to strontium titanate through chemical solution deposition. This study investigated changes in the ordinary and extraordinary refractive index
no and
ne induced in these films by an electric field using the prism-coupling method. In the (100) epitaxial PZT 30/70 film, anisotropic electro-optic effects arise from the Pockels effect. The isotropic electro-optic effect, which is
no =
ne , was achieved on (100) epitaxial PLZT 8/65/35 and PZT 70/30 films.

Abstract: In this study, BiFeO3 (BFO) epitaxial film was deposited on SrRuO3 (100)/SrTiO3 (100) substrates using pulsed laser deposition (PLD). Phase pure BFO thin film was obtained. Introducing a mask between the target and substrate in PLD improved the surface roughness from 47.8 nm (RMS, without mask) to 7.7 nm (RMS, with mask). The composition and electrical properties of BFO thin film were assessed after annealing for 1 h in Ar, N2, or O2 atmosphere at 600°C. The P-E hysteresis properties improved only in the O2 atmosphere. After annealing under O2 atmosphere, the leakage current decreased from 6.1 × 10-2 A/cm to 2.9 × 10-2 A/cm at 200 kV/cm, as in the other annealing atmospheres, but 2Pr increased from 35 BC/cm2 to 50 BC/cm2.

Abstract: Epitaxial Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) thin films for electrooptic applications were fabricated on a Si substrate using buffer layers. The PMN-PT/SrRuO3/SrTiO3/(La,Sr)CoO3/CeO2 /YSZ/Si hetrostructure was fabricated by pulsed laser deposition. A PMN-PT thin film with a thickness of 2μm was successfully deposited. The optical characteristics of PMN-PT epitaxial film were measured by prism coupling method. The morphology of the PMN-PT films was drastically improved by introducing a mask between the target and substrate during the deposition. The PMN-PT thin film showed a columnar structure, where the width of each column was approximately 180nm. A refractive index of 2.48 with zero bias voltage was obtained for the epitaxial PMN-PT thin film using the prism coupler method.