La Content Dependence of Electrooptic Properties of Polycrystalline (Pb,La)(Zr_0.65,Ti_0.35)O₃ Thick Films

Abstract

The systematic investigation of the electrical, optical and electrooptic properties of lanthanum-substituted lead zirconate titanate (PLZT) films was carried out. Polycrystalline PLZT films with various La and Pb contents were prepared at various sintering temperatures by chemical solution deposition (CSD). Among the 135 conditions we examined, a sintering temperature of 700 °C and a Pb content ratio of 125% relative to a stoichiometric value were optimum for preparing well-filled films. The maximum polarization monotonically decreased with increasing La content, while the dielectric constant change was maximum at a La content of 6 mol %. The refractive indexes of the PLZT films were estimated to be in the range from 2.35 to 2.42 at 630 nm. The refractive index change due to the application of a DC bias voltage was maximum at a La content of 0 mol %, monotonically decreased with increasing La content, and strongly correlated with the maximum polarization change. Therefore, we concluded that the electrooptic effect in the PLZT films is mainly caused by the reconfiguration of the domain structure in the films.

Fabrication of conductive oxide polycrystalline BaPbO3 films by chemical solution deposition and their electrical resistivity

“…The lowest electrical resistivity of approximately 3 μΩ·m was achieved at the annealing temperature of 873 and 923 K. Above 973 K, the electric resistivities monotonically increased and reached to 80 μΩ·m at 1073 K, although well crystallized single phase of BaPbO 3 films had formed at that temperature. According to our previous study, [8] polycrystalline Pb(Zr,Ti)O 3 films were crystallized at around 923 K, suggests that BaPbO 3 films is suitable for bottom electrode of the Pb(Zr,Ti)O 3 films. Therefore, we fabricated the Pb (Zr,Ti)O 3 films on the BaPbO 3 film electrodes using the same technique in this study and evaluated the ferroelectric properties.…”

Influence of orientation on the electro-optic effect in epitaxial Y-doped HfO2 ferroelectric thin films

“…[2][3][4][5]10) To date, EO properties and their device performance for various materials, such as (Ba, Sr)TiO 3 (BST), (Pb, La)(Zr, Ti)O 3 , and relaxor ferroelectrics in bulk and thin-film forms, have been explored. 2,4,[11][12][13][14][15][16][17][18][19][20][21][22][23] Among them, LiNbO 3 is widely used in EO devices owing to its high EO coefficient, and large single crystals with high optical quality can be grown. [24][25][26] The growth of high-quality thin films of such materials on Si, i.e.…”

Composition dependence of electrooptic property of epitaxial (Pb,La)(Zr,Ti)O3 films

“…We previously reported that the PLZT film with La content of 2 at.%, not 89 at.%, and Ti/(Zr + Ti) ratio of 40% is an optimum composition for getting high electrooptic coefficient and smooth surface in polycrystalline films by investigating La content and Zi/Ti ratio dependences of electrooptic properties. 4), 5) On the other hand, Ishii et al reported that the highest electrooptic coefficient was obtained in the epitaxial PLZT film with La content of 9 at.%. 6) These results show that the La contents dependence of electrooptic properties has different trend between polycrystalline films and epitaxial films, and suggest that the Zr/Ti ratio dependence may also have different trend.…”