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.

Preparation of highly c-axis oriented Sr0.6Ba0.4Nb2O6 thin films grown on Silicon substrate by the sol–gel process

2006 ◽  
Vol 99 (1) ◽  
pp. 10-14 ◽  
Author(s):  
Zhiru Shen ◽  
Hui Ye ◽  
C.L. Mak ◽  
K.H. Wong ◽  
T.Y. Yum ◽  
...  
Keyword(s):  
Thin Films ◽  
Silicon Substrate ◽  
Sol Gel ◽  
Sol Gel Process

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.

scholarly journals Local Fatigue Evaluation in PZT Thin Films with Nanoparticles by Piezoresponse Force Microscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-9
Author(s):  
B. S. Li
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Precursor Solution ◽  
Grain Morphology ◽  
Piezoresponse Force Microscopy ◽  
Lead Zirconate ◽  
Fatigue Performance ◽  
Pzt Thin Films

Lead zirconate titanate (PZT) thin films with the morphotropic phase boundary composition (Zr/Ti = 52/48) have been prepared using a modified diol-based sol-gel route by introducing 1–5 mol% barium titanate (BT) nanoseeds into the precursor solution on platinized silicon substrates (Pt/Ti/SiO2/Si). Macroscopic electric properties of PZT film with nanoparticle showed a significant improvement of ferroelectric properties. This work aims at the systematic study of the local switching polarization behavior during fatigue in PZT films with and without nanoparticles by using very recent developed scanning piezoelectric microscopy (SPM). We show that the local fatigue performance, which is characterized by variations of local piezoloop with electric cycles, is significantly improved by adding some nanoseeds. It has been verified by scanning electron microscope (SEM) that the film grain morphology changes from columnar to granular structure with the addition of the nanoseeds. On the other hand, the existence of PtxPb transition phase, which existed in interface at early crystallization stage of pure PZT thin film, deteriorates the property of the interface. These microstructures and the interfaces of these films significantly affect the electrons injection occurred on the interfaces. The domain wall pinning induced by injected electrons and the succeeding penetration into the films is discussed to explain the fatigue performance.

Synthesis and Ferroelectric Properties of Sr- and Nb-codoped Bi4−xSrxTi3−xNbxO12 Thin Films by Sol-Gel Method

2001 ◽  
Vol 688 ◽  
Author(s):  
Hirofumi Matsuda ◽  
Takashi Iijima ◽  
Hiroshi Uchida ◽  
Isao Okada ◽  
Takayuki Watanabe ◽  
...  
Keyword(s):  
Thin Films ◽  
Curie Temperature ◽  
Spin Coating ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Metal Alkoxide ◽  
Gel Method ◽  
Maximum Value ◽  
Chemical Solutions

AbstractFerroelectric Bi4Ti3O12 (BIT) thin films were modified by the substitution of Sr2+ ions for Bi3+ ions and of Nb5+ for Ti4+ (codoping) by spin-coating and decomposition of chemical solutions of metal-alkoxide materials (the nominal compositions of Bi4−xSrxTi3−xNbxO12 where x=0.0, 0.5, 1.0, 1.5). Single-phase thin films were crystallized above 550°C with BIT-type structure. The ferroelectric properties were found, though, with the values of Pr=10 μC/cm2 Ec=100 kV/cm, εr=300, and tanδ<5 % for Bi3.5Sr0.5Ti2.5Nb0.5O12 (x=0.5) annealed at 650 °C. Perhaps due to the lowering of the Curie temperature with increasing x, the maximum value of δr increased.

Preparation of LiTaO3 Nano-Crystalline Films by Sol-Gel Process

2012 ◽  
Vol 531-532 ◽  
pp. 446-449 ◽  
Author(s):  
Jun Gou ◽  
Jun Wang ◽  
Ze Hua Huang ◽  
Ya Dong Jiang
Keyword(s):  
Thin Films ◽  
High Performance ◽  
Detection System ◽  
Sol Gel ◽  
Precursor Solution ◽  
Film Material ◽  
Nano Crystalline ◽  
Sol Gel Process ◽  
Crystalline Films ◽  
P Type

Lithium tantalite (LiTaO3) thin film material shows good feasibility and potential for the application of high-performance detection system. In this paper, sol-gel process of LiTaO3 thin films on p-type (111) silicon substrates was described. Stable precursor solution with a desired viscosity was obtained using lithium acetate (LiAc) and tantalum ethoxide (Ta(OC2H5)5) as starting materials. Heat treatment process was optimized to fabricate LiTaO3 films of high crystallinity. Higher crystalline quality films were obtained when each spin-coating process was followed by an annealing operation. Microstructures and crystallization properties of LiTaO3 thin films were further studied. Nano-crystalline films were obtained after annealing at 700 °C for 5 min. The experimental results indicated that the crystallinity and mean grain size of LiTaO3 thin films were proportional to the film thickness.

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