Ferroelectric thin films with complex composition of PNN–PZN–PMN–PZ–PT and excess NiO

2008 ◽  
Vol 23 (2) ◽  
pp. 536-542 ◽  
Author(s):  
Phoi Chin Goh ◽  
Kui Yao ◽  
Zhong Chen
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Oxide System ◽  
Ferroelectric Thin Films ◽  
Ionic Radii ◽  
Pt Complex ◽  
The Stability

Ferroelectric thin films of the 0.1Pb(Ni1/3Nb2/3)O3–0.35Pb(Zn1/3Nb2/3)O3–0.15Pb (Mg1/3Nb2/3)O3–0.1PbZrO3–0.3PbTiO3 (PNN–PZN–PMN–PZ–PT) complex oxide system were prepared on Pt/Ti/SiO2/Si substrates using a polymer-modified sol-gel method followed by a rapid thermal annealing (RTA) process. It was found that the addition of excess NiO is effective in stabilizing the perovskite phase while suppressing the pyrochlore phase. The crystalline structure and morphology of the films with different amounts of access NiO were studied with x-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The electrical properties, including dielectric, ferroelectric, and piezoelectric, showed a significant improvement with excess NiO. The film sample with 3 mol% of excess NiO exhibited optimized electrical properties. Different parameters, including tolerance factors on the basis of ionic radii, electronegativity differences between cations and anions, and oxygen bond valences, were applied to analyze the stability of the perovskite phase with different amount of excess NiO. Analysis results indicated that only the bond-valence theory could explain the effect of excess NiO on the stability of the perovskite phase under the assumption that the excess Ni2+ entered the A sites of the perovskite structure.

The role of excess Pb and PbO overpressure on the microstructural development in polycrystalline PZT thin films

1994 ◽  
Vol 52 ◽  
pp. 582-583
Author(s):  
M. J. Lefevre ◽  
D. B. Dimos ◽  
J. S. Speck
Keyword(s):  
Thin Films ◽  
Data Storage ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Optical Data Storage ◽  
Optical Data ◽  
Microstructural Development

Ferroelectric thin films have recently received considerable attention because of their potential in a range of device applications including both volatile and non-volatile memories, optical data storage, and other electrooptic applications (e.g. waveguides, switches, and modulators). The Pb-based perovskites, such as Pb(Zr,Ti)O3, have many properties that make them attractive for such applications because of their high switchable remanant polarization. In addition, many applications require integration of the ferroelectric with semiconductors. In our work we are studying the crystallization sequence of PZT 40/60 (PbZr0.40Ti0.60O3) grown on platinized silicon substrates, with an overall structure given as PZT/Pt/Ti/SiO2Si. The Ti and Pt are sequentially evaporated onto the oxidized Si substrate. Alkoxide-derived films are spun onto these substrates to form a dry amorphous gel2. The crystallization of the sol-gel film proceeds upon heating to temperatures in the range of 400-700°C. Lead volatility is one of the critical issues in the crystallization of Pb-based perovskite thin films. We have carried out a systematic study on the role of a lead atmosphere in crystallization for PZT (40/60). When heat treated the film forms a transitory pyrochlore phase at intermediate temperatures before transforming to the perovskite phase. This non-ferroelectric pyrochlore phase may stabilize if lead stoichiometry is not maintained, leading to poor optical and ferroelectric properties in the thin films.

Influence of Geometrical Parameters on the Electrical Properties of Ferroelectric Thin Films

1991 ◽  
Vol 243 ◽  
Author(s):  
S.P. Faure ◽  
P. Gaucher ◽  
J.P. Ganne
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Remanent Polarization ◽  
Sol Gel ◽  
Mean Value ◽  
Ferroelectric Thin Films ◽  
Geometrical Parameters ◽  
Electrical Characteristics ◽  
Electrode Size ◽  
Sol Gel Process

AbstractFerroelectric thin films of PbZr0.5Ti0.5O3 were prepared by sol-gel process. Top electrodes of different sizes were deposited on thin films in order to study their influence on electrical properties. Histograms of the measured electrical characteristics are related to the electrode sizes. By reducing the electrode size, it is possible to improve the electrical properties of the film. Various properties, such as remanent polarization Pr and coercive voltage Vc, were measured statistically in order to show the evolution of their mean value and of their variance with the electrode size.

Effects of Annealing Temperature on Structure and Properties of PLBZT Ferroelectric Thin Films Synthesized by Sol-Gel Processing

2012 ◽  
Vol 602-604 ◽  
pp. 1461-1464
Author(s):  
Hua Wang ◽  
Li Liu ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Shang Ju Zhou
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Ferroelectric Thin Films ◽  
Structure And Properties ◽  
Maximum Value ◽  
Processing Effects ◽  
Gel Processing

[Pb0.95(La0.6Bi0.4)0.05][Zr0.53Ti0.47]O3 (PLBZT) ferroelectric thin films have been synthesized on ITO-coated glass by sol-gel processing. Effects of annealing temperature on structure and properties of PLBZT have been investigated. With the increase of annealing temperature from 500°C to 550°C, the remanent polarization Pr increase slightly to the maximum value of 25.4μC/cm2 due to the improvement in crystallization of PLBZT films. However, when the annealing temperature is more than 550°C, the pyrochlore phase appear and degrade the Pr of PLBZT thin films. The lowest leakage current density of 1.8×10-9 A/cm2 can be observed in PLBZT thin films when the annealing temperature is 550°C.

Effect of Electrode Materials on the Microstructure of Sol-Gel Derived Pzt Ferroelectric Thin Films

1991 ◽  
Vol 243 ◽  
Author(s):  
Sharon A. Myers ◽  
Edward R. Myers
Keyword(s):  
Thin Films ◽  
Metal Oxide ◽  
Electrode Materials ◽  
Volume Fraction ◽  
Sol Gel ◽  
Oxide Films ◽  
Pyrochlore Phase ◽  
Ferroelectric Thin Films ◽  
Metal Oxide Films ◽  
Wide Range

AbstractA wide range of electrode materials have been investigated for use in ferroelectric-silicon CMOS technology. Numerous metal and metal-oxide films were deposited on silicon substrates and coated with sol-gel derived ferroelectric thin films. The films were sintered in either a diffusion furnace or by rapid thermal processing. Transmission electron microscopy was used to investigate the evolution of the resulting ferroelectric thin film microstructure and ferroelectric / electrode material interactions.Microstructural differences such as the volume fraction of the ferroelectric perovskite and pyrochlore phase, domains and grain structure are correlated with electrical results. A strong microstructural dependence on the substrate was found for the Cr, Zr, Hf and Ni electrode materials. In general, chromium and other metal-oxide films had high leakage currents and large volume fractions of the non-ferroelectric pyrochlore phase. Nickel electrodes displayed the best electrical results, but the microstructure is very different from the other ferroelectric films.

Electrical Properties of Amorphous Thin Films of Ferroelectric Oxides Prepared by Sol-Gel Technique

1993 ◽  
Vol 310 ◽  
Author(s):  
Yuhuan Xu ◽  
Ren Xu ◽  
Chih-Hsing Cheng ◽  
John D. Mackenzie
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Ferroelectric Thin Films ◽  
Amorphous Thin Films ◽  
Crystalline Films ◽  
Gel Technique ◽  
Ferroelectric Oxides

AbstractAmorphous thin films of ferroelectric oxides including lead zirconate titanate (PZT), barium titanate (BaTiO3) and lithium niobate (LiNbO3) on several kinds of substrates were prepared by a sol-gel technique. The heat-treatment temperatures for preparation of amorphous thin films were much lower than those for the corresponding crystalline ferroelectric thin films. Electrical properties of these amorphous thin films were measured and compared with those of corresponding crystalline films. These amorphous thin films exhibited ferroelectric-like behavior. A model of the microstructure of these films is proposed.

scholarly journals Robust ferroelectricity enhancement of PZT thin films by a homogeneous seed layer

2021 ◽  
Author(s):  
jie jiang ◽  
Lei Liu ◽  
Kuo Ouyang ◽  
Zhouyu Chen ◽  
Shengtao Mo ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Remanent Polarization ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Pzt Thin Films ◽  
Large Dielectric Constant ◽  
Sol Gel Process ◽  
A New Technique

Abstract With its excellent ferroelectric properties such as large dielectric constant and large remanent polarization, PZT thin films are extensively used in micro-sensors and other devices. In this study, the sol-gel process was used to fabricate Pb(Zr0.52Ti0.48)O3 thin films with Pb(ZrxTi1−x)O3 seed islands. The experimental consequences demonstrate that all the Pb(Zr0.52Ti0.48)O3 thin films with Pb(ZrxTi1−x)O3 seeds show pure perovskite phase with no other impurity phases, and the electrical properties of Pb(Zr0.52Ti0.48)O3 thin films modified by Pb(ZrxTi1−x)O3 seed islands with different Zr/Ti ratios are improved, such as remanent polarization increased, dielectric properties increased, coercive electric field decreased, leakage current density decreased, etc. In particular, the electrical properties of the Pb(Zr0.52Ti0.48)O3 thin films with Pb(ZrxTi1−x)O3 seed islands are the most optimal when the x is 0.52. This paper provides a new technique for optimizing the electrical properties of PZT thin films, which is of great significance for breaking through the bottleneck of the development of ferroelectric memory.

Optical Properties of Sol-Gel Derived PbTiO3 and PbZr1−xTiO3 Ferroelectric Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Xiangjian Meng ◽  
Zhiming Huang ◽  
Hongjian Ye ◽  
Jiangong Cheng ◽  
Pingxiong Yang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Wavelength Region ◽  
Ferroelectric Thin Films ◽  
Silicon Substrates ◽  
X Rays ◽  
Phonon Modes ◽  
Infrared Reflection Spectroscopy

AbstractWith sol-gel processing and rapid thermal annealing (RTA), crack-free PbTiO3 and PbZr1−xTixO3(x=0.2-0.8) ferroelectric thin films were prepared on Si(100) and Pt/Ti/SiO2/Si(100) substrates respectively. Results from x-ray diffraction (XRD) show that the films are single perovskite phase structure. Scanning electron microscopy (SEM) was used to determine the grain sizes of the thin films. Energy dispersive spectroscopy (EDS) of x rays was used to analyze the composition of the films. From infrared reflection spectroscopy in the wavelength region of 40-700 cm−1 at 300K, the vibrational mode frequencies in PbTiO3 thin films on silicon substrates were obtained at the wavenumbers of 79, 155, 206, 298, 344, 461, 520 and 621 cm−1. Among these phonon modes, the modes at 298 and 461 cm−1 have not been reported before. The infrared optical constants and the thickness of PZT thin films on Pt/Ti/SiO2/Si(100) substrates were directly measured in the wavelength region of 2-12μm by an automatic wavelength swept infrared spectroscopic ellipsometer. These constants include: refractive index (n), extinction coefficient (k), thickness of the films and absorption coefficient (α). Possible correlation among the processing, microstructure and optical properties of the thin films were discussed.

Epitaxial Growth of Ferroelectric Pb(Mgl/3Nb2/3)03 Film by Sol-Gel Method

1990 ◽  
Vol 204 ◽  
Author(s):  
Kumi Okuwada ◽  
Shin-Ichi Nakamura ◽  
Motomasa Imai ◽  
Keiichi Kakuno
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Growth Process ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Preferred Orientation ◽  
Ferroelectric Thin Films ◽  
Metal Alkoxides ◽  
Gel Method ◽  
Sol Gel Method

ABSTRACTFerroelectric thin films, which are Pb(Mgl/3Nb2/3)03 (PMN) and Pb(Mgl/3Nb2/3)03 - PbTiO3 (PMN-PT) in the perovskite phase, were obtained by the sol-gel method with metal alkoxides. The films had highly preferred orientation on substrates whose interplanar spacings are close to that for the perovskite structures in PMN and PMN-PT. Epitaxial growth process in PMN film was investigated.

Low Temperature Crystallization of Bismuth Layer-Structured Ferroelectric Thin Films Using Lead Titanate Sol-Gel Templating Technique and Their Electrical Properties

2003 ◽  
Vol 784 ◽  
Author(s):  
Junichi Karasawa ◽  
Takeshi Kijima ◽  
Eiji Natori ◽  
Tatsuya Shimoda
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Layered Structure ◽  
Crystallization Temperature ◽  
Lead Titanate ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Doping Amount ◽  
Gel Network

ABSTRACTThe crystal structure and electrical properties of lead titanate (PbTiO3: PT) sol-gel network templated bismuth layer-structured ferroelectric (BLSF) thin films were systematically investigated as a function of the doping amount of lead titanate sol-gel solution and annealing temperature. The starting solutions of lead titanate sol-gel templated BLSF were prepared by adding lead titanate sol-gel solution to BLSF solutions such as strontium bismuth tantalate (SrBi2Ta2O9: SBT), bismuth titanate (Bi4Ti3O12: BiT) and lanthanum-doped bismuth titanate ((Bi,La)4Ti3O12: BLT). These solutions were spin-coated on platinized silicon wafers and pyrolized on a hot plate, then crystallized at 550°C – 738°C by RTA (Rapid Thermal Annealing). The crystallized films with sputtered platinum top electrodes were post-annealed for electrical property measurements. In the case of SBT-PT, it was found that the added lead titanate so-gel network has no remarkable effect on lowering the BLSF (m=2) crystallization temperature but rather enhances the pyrochlore phase. In the case of BiT-PT, the bismuth layered-structure was confirmed at the temperature down to 550°C as the amount of lead titanate sol-gel network is increased. The major layered-structure, however, was not desired m=3, but unexpected m (e.g m=4 or higher). In the case of BLT-PT, lowering the BLSF (m=3) crystallization temperature down to 638°C was finally achieved within proper amount of lead titanate sol-gel network without drastic drop of ferroelectricity. A 2Pr of 32 μC/cm2 was obtained in 0.96BLT-0.04PT thin film.

Studies on the Preparation and Characterization of Ferroelectric PLZT Film Capacitors

2011 ◽  
Vol 110-116 ◽  
pp. 5483-5486
Author(s):  
Li Liu ◽  
Hua Wang ◽  
Ji Wen Xu ◽  
Ming Fang Ren ◽  
Ling Yang
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Plzt Thin Films ◽  
Coercive Electric Field

(Pb0.92La0.08)(Zr0.65Ti0.35) O3(PLZT) thin films were fabricated on indium-doped tin oxide (ITO)-coated glass substrates to create transparent capacitor by the sol-gel method following annealing process. X-ray diffraction analysis shows that the PLZT thin films are polycrystalline with a single perovskite phase at 650°C. The ferroelectric, electrical and optical properties of these films were investigated in detail as a function of annealing temperature. Measurements with the PLZT films annealed at 650°C yielded the following: relative permittivity≈775 and dielectric loss (tanδ) ≈0.054, leakage current of 7.1× 10-9A, and remanent polarization of 38 μC/cm2 and the coercive electric field of 55 kV/cm and transparency of 88%. The pure perovskite films exhibit better properties than those films which have some fraction of pyrochlore phase.

Sign in / Sign up

Export Citation Format

Share Document