Structural, Dielectric and Pyroelectric properties of Lanthanum modified Lead Titanate Thin Films

2004 ◽  
Vol 811 ◽  
Author(s):  
Sonalee Chopra ◽  
Seema Sharma ◽  
T.C. Goel ◽  
R.G. Mendiratta
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Mechanical Stability ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Pyroelectric Coefficient ◽  
Structural Investigations ◽  
Glass Substrates

ABSTRACTFerroelectric lead lanthanum titanate (Pb1−xLaxTi1−x/4O3) (PLTx) thin films (x=0.04,0.08 and 0.12) have been prepared by sol-gel spin coating process on ITO coated 7059 Corning glass substrates. Investigations have been made on the crystal structure, surface morphology, dielectric and ferroelectric properties of the thin films. For a better understanding of the crystallization mechanism, the structural investigations were carried out at various annealing temperatures (350°C, 450°C, 550°C and 650°C). Characterization of these films by X-ray diffraction shows that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. Replacement of lanthanum in lead titanate results in reduction of tetragonal ratio (c/a), resulting in better mechanical stability. Microstructural analysis of the films are carried out by taking the Atomic Force Microscope (AFM) pictures. AFM images are characterized by slight surface roughness with a uniform crack free, densely packed structure. Dielectric, pyroelectric and ferroelectric studies carried out on these films have been reported. Dielectric constant and pyroelectric coefficient increase while Curie temperature decreases with increase in La content. The pyroelectric figures of merit of the films have also been calculated which suggest that 8% lanthanum is best suited material for pyroelectric detectors owing to its high pyroelectric coefficient (∼ 29nC/cm2 K), high voltage responsivity (∼420Vcm2/J), high detectivity (∼1.04×10−5Pa−1/2) and low variation of pyrocoefficient with temperature.

Characterisation of Ferroelectric Lithium Tantalate Thin Films Prepared by a Sol-Gel Process

1993 ◽  
Vol 321 ◽  
Author(s):  
Chianping Ye ◽  
Paul Baude ◽  
Dennis L. Polla
Keyword(s):  
Thin Films ◽  
Curie Temperature ◽  
Single Crystal ◽  
Silicon Substrate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Precursor Solution ◽  
Pyroelectric Coefficient ◽  
Crystal Silicon ◽  
Sol Gel Process

ABSTRACTThin LiTaO3 films were prepared by spin coating of polymerized sol-gel precursor solution. Films have been deposited on single crystal silicon substrate, Ti/Pt or SiO2 coated silicon substrate. Films were characterized by x-ray diffraction, dielectric and pyroelectric Measurements. High Curie temperature (above 550 °C) was assumed for LiTaO3 thin films from the temperature dependence of dielectric constant. Replacing 35% of tantalum by titanium atoms in the LiTaO3 precursor solution has resulted the thin films with Curie temperature of 330 °C. The lower Curie temperature leads to the larger pyroelectric coefficient at room-temperature, which is more than double that of the undoped LiTaO3 thin films. The dielectric, pyroelectric, and ferroelectric properties have been compared to the single crystal LiTaO3 and ceramic Li0.91Ta0.73Ti0.36O3. LiTaO3 thin films are available by sol-gel process at low temperature, and their properties may possibly be controlled by varying the composition of the sol-gel precursor solution.

Dielectric and I-V Characteristic of Lead Titanate Thin Films Prepared on ITO Glass Substrate

2015 ◽  
Vol 1109 ◽  
pp. 461-465 ◽  
Author(s):  
Nurbaya Zainal ◽  
Mohd Hafiz Wahid ◽  
Mohammad Rusop
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
High Performance ◽  
Annealing Temperature ◽  
Low Cost ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Ito Glass

Performance of lead titanate, (PbTiO3) thin films have been successfully investigated on microstructural properties, I-V characteristic, dielectric properties, and ferroelectric properties. PbTiO3offers variety of application as transducer, ferroelectric random access memory, transistor, high performance capacitor, sensor, and many more due to its ferroelectric behavior. Preparation of the films are often discussed in order to improve the structural properties, like existence of grain boundaries, particle uniformity, presents of microcrack films, porosities, and many more. Yet, researchers still prepare PbTiO3thin films at high crystallization temperature, certainly above than 600 ̊C to obtain single crystal perovskite structure that would be the reason to gain high spontaneous polarization behavior. Although this will results to high dielectric constant value, the chances that leads to high leakage current is a major failure in device performance. Thus, preparation the thin films at low annealing temperature quite an essential study which is more preferable deposited on low-cost soda lime glass. The study focuses on low annealing temperature of PbTiO3thin films through sol-gel spin coating method and undergo for dielectric and I-V measurements.

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.

FERROELECTRIC PROPERTIES OF CaBi4Ti4O15 THIN FILMS ON ITO/GLASS SUBSTRATES PREPARED BY SOL-GEL TECHNOLOGY

2012 ◽  
Vol 06 ◽  
pp. 91-97
Author(s):  
CHIEN-MIN CHENG ◽  
MING-CHANG KUAN ◽  
KAI-HUNAG CHEN ◽  
JEN-HWAN TSAI
Keyword(s):  
Thin Films ◽  
Leakage Current Density ◽  
Current Density ◽  
Coercive Field ◽  
Glass Substrate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Electrical Field ◽  
Glass Substrates ◽  
Ito Glass

In this study, ferroelectric CaBi 4 Ti 4 O 15 (CBT) thin films prepared by sol-gel method and deposited on ITO/glass substrates for applications in system-on-panel (SOP) devices were fabricated and investigated. The electrical and physical characteristics of as-deposited and annealed CBT thin films for metal-ferroelectric-metal (MFM) structures was discussed and investigated. In addition, the ferroelectric properties in annealed CBT thin films on ITO/glass substrate showed and exhibited clear polarization versus electrical field curves. From p - E curves, the 2 P r value and coercive field of annealed CBT thin films were calculated to be 10μC/cm2 and 180 kV/cm, respectively. Finally, the maximum capacitance, leakage current density, and transmittance within the ultraviolet-visible (UV–vis) spectrum were also investigated and discussed.

Pyrochlore-to-perovskite transformation during rapid heating of sol-gel (Pb,La)TiO3 thin films

1999 ◽  
Vol 14 (11) ◽  
pp. 4302-4306 ◽  
Author(s):  
Miguel Algueró ◽  
M. Lourdes Calzada ◽  
Lorena Pardo
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Thermal Treatment ◽  
Heating Rate ◽  
Lead Titanate ◽  
Perovskite Phase ◽  
Rapid Heating ◽  
Sol Gel ◽  
Pyrochlore Structure ◽  
Gel Method

Phases appearing in lanthanum-modified lead titanate thin films prepared by a diol-based sol-gel method and crystallized by rapid heating were studied. The results clearly indicate that a phase transformation from a pyrochlore structure to the perovskite phase occurs in Pb-deficient films during the thermal treatment, which involves a heating rate higher than 500 °C min−1. The rate of this transformation is a function of the lead content of the films, decreasing as lead volatilizes. Temperatures higher than 650 °C or soak times longer than 2 h make possible the complete pyrochlore-to-perovskite transformation without any lead excess in the films.

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.

Pyrochlore-perovskite phase development of sol-gel derived modified lead titanate thin films

1995 ◽  
Vol 29 (1-4) ◽  
pp. 197-200 ◽  
Author(s):  
M.L. Calzada ◽  
J. Mendiola ◽  
F. Carmona ◽  
R. Sirera
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Phase Development
Sign in / Sign up

Export Citation Format

Share Document