Ryoji Makabe

Relationship between crystal structure and chemical composition of PbTiO3 thin films prepared by sputter-assisted plasma CVD

PbTiO3 thin films were prepared by sputter-assisted plasma chemical vapor deposition (CVD) on Pt-coated glass substrates at a substrate temperature of 500°C. As the source materials, a Pb metal target, TiCl4 gas and O2 gas were used. The crystal structures of the films changed from a pyrochlore phase to a perovskite one, and to a PbO (red) one with increasing Pb/Ti atomic ratio.

Optical Constants of HgTe and HgSe

The optical constants of HgTe and HgSe are determined in the photon energy region 1.7~3.5 eV from ellipsometric measurements at room temperature. The structures associated with the E1 and E1+Δ1 band edges are found in the extinction coefficient spectra at energy values nearly coincident with the data of the normal incidence reflectivity for both materials. Tentative surface film corrections are made at several photon energies.

Preparation of PbTiO3 Thin Films by Sputter Assisted Plasma Chemical Vapor Deposition Method

Lead titanate thin films were prepared by sputter assisted plasma chemical vapor deposition method. Metallic lead as a sputtering target and titanium tetrachloride carried by hydrogen gas were used as lead and titanium sources, respectively. Without post thermal annealing, ferroelectric perovskite phase were obtained at substrate temperature of 550°C on platinum coated glass substrate with the deposition rate of about 70 nm/min. Surface of the film was smoother than the one prepared by post thermal annealing.

c-Axis Oriented PbTiO 3 Thin Films on MgO and Their Microstructure

PbTiO 3 thin films were prepared on MgO(100) substrates using a conventional rf magnetron sputtering system with a powder target. By optimizing the deposition conditions, highly c-axis oriented PbTiO 3 epitaxial films were obtained. The c-axes of the domains in the films were normal to the substrate, but some a-axes were tilted from the normal towards (100) directions with a particular angle and fourfold symmetry. From the tilt angle and the tilt directions, it is concluded that 90° domain structures were formed by twins, the domain walls of which were (101) twin boundaries.