Ferroelectric nanocomposite with high dielectric constants

2002 ◽  
Vol 755 ◽  
Author(s):  
Mai T.N. Pham ◽  
B.A. Boukamp ◽  
H.J.M. Bouwmeester ◽  
D.H.A. Blank
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Ferroelectric Material ◽  
Metallic Phase ◽  
Dielectric Constants ◽  
Effective Dielectric Constant ◽  
X Ray Diffraction ◽  
Non Volatile Memory ◽  
Colloidal Method ◽  
High Dielectric

ABSTRACTComposites between ferroelectric material and a dispersed metal phase are of great interest due to the improvement in dielectric properties for such applications as high capacitance capacitors, non-volatile memory, ect. Using a colloidal method, Pt particles with a size of 3–5 nm were dispersed homogeneously in a PZT (PbZr0.53Ti0.43O3) matrix. No unwanted reaction phase between PZT and Pt during sintering at 1150 °C could be detected by X-ray diffraction. Electrical properties were investigated by impedance spectroscopy measurement. The effective dielectric constant increased remarkably as a power function of Pt volume content and can be described by the percolation theory. At 25 vol.% of Pt the dielectric constant of the composite is 4 times larger than that of pure PZT. The temperature dependence of the electrical properties is also influenced by the metallic phase fraction.

scholarly journals Prospects for the Development of High Energy Density Dielectric Capacitors

2021 ◽  
Vol 11 (17) ◽  
pp. 8063
Author(s):  
Andrew Burke
Keyword(s):  
Dielectric Constant ◽  
Energy Density ◽  
Breakdown Strength ◽  
High Energy ◽  
Dielectric Constants ◽  
Polymer Materials ◽  
High Energy Density ◽  
Effective Dielectric Constant ◽  
High Dielectric ◽  
Very High

In this paper, the design of high energy density dielectric capacitors for energy storage in vehicle, industrial, and electric utility applications have been considered in detail. The performance of these devices depends primarily on the dielectric constant and breakdown strength characteristics of the dielectric material used. A review of the literature on composite polymer materials to assess their present dielectric constants and the various approaches being pursued to increase energy density found that there are many papers in which materials having dielectric constants of 20–50 were reported, but only a few showing materials with very high dielectric constants of 500 and greater. The very high dielectric constants were usually achieved with nanoscale metallic or carbon particles embedded in a host polymer and the maximum dielectric constant occurred near the percolation threshold particle loading. In this study, an analytical method to calculate the dielectric constant of composite dielectric polymers with various types of nanoparticles embedded is presented. The method was applied using an Excel spreadsheet to calculate the characteristics of spiral wound battery cells using various composite polymers with embedded particles. The calculated energy densities were strong functions of the size of the particles and thickness of the dielectric layer in the cell. For a 1000 V cell, an energy density of 100–200 Wh/kg was calculated for 3–5 nm particles and 3–5 µ thick dielectric layers. The results of this study indicate that dielectric materials with an effective dielectric constant of 500–1000 are needed to develop dielectric capacitor cells with battery-like energy density. The breakdown strength would be 300–400 V/µ in a reverse sandwich multilayer dielectric arrangement. The leakage current of the cell would be determined from appropriate DC testing. These high energy density dielectric capacitors are very different from electrochemical capacitors that utilize conducting polymers and liquid electrolytes and are constructed much like batteries. The dielectric capacitors have a very high cell voltage and are constructed like conventional ceramic capacitors.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

Ionic Conductivities of Doped CeO2 Thin Films as Related to Their Microstructure

1995 ◽  
Vol 411 ◽  
Author(s):  
Chunyan Tian ◽  
Siu-Wai Chan
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Ionic Conductivities ◽  
Dielectric Constants ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Fine Grain ◽  
Brick Layer Model ◽  
Columnar Grain ◽  
Beam Deposition

ABSTRACTThin films of 4% Y2O3 doped CeO2/Pd film/(001)LaA103 with a very low pinhole density were successfully prepared using electron-beam deposition technique. The microstructure of the films was characterized by x-ray diffraction and the electrical properties were studied as a function of temperature with AC impedance spectroscopy. A brick layer model was adopted to correlate the electrical properties to the microstructure of the films, which can be simplified as either a series or a parallel equivalent circuit associated with either a fine grain or a columnar grain structure, respectively. The conductivities of the films fell between the conductivities derived from the two circuit models, suggesting that the films are of a mixed fine grain and columnar grain structure. The measured dielectric constants of the films were found smaller than that of the bulk.

scholarly journals STRUCTURAL AND ELECTRICAL PROPERTIES OF TANTALUM PENTAOXIDE (Ta2O5) THIN FILMS – A REVIEW

2013 ◽  
Vol 22 ◽  
pp. 564-569
Author(s):  
KANTA RATHEE ◽  
B. P. MALIK
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Metal Oxide ◽  
High Dielectric Constant ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Structural And Electrical Properties ◽  
High Dielectric ◽  
Deposited Films

Down scaling of complementary metal oxide semiconductor transistors has put limitations on silicon dioxide to be used as an effective dielectric. It is necessary to replace the SiO 2 with a physically thicker layer of oxides of high dielectric constant. Thus high k dielectrics are used to suppress the existing challenges for CMOS scaling. Many new oxides are being evaluated as gate dielectrics such as Ta2O5 , HfO2 , ZrO2 , La2O3 , HfO2 , TiO2 , Al2O3 , Y2O3 etc but it was soon found that these oxides in many respects have inferior electronic properties to SiO2 . But the the choice alone of suitable metal oxide with high dielectric constant is not sufficient to overcome the scaling challenges. The various deposition techniques and the conditions under which the thin films are deposited plays important role in deciding the structural and electrical properties of the deposited films. This paper discusses in brief the various deposition conditions which are employed to improve the structural and electrical properties of the deposited films.

scholarly journals An Investigation of the Electrical Behavior of Thermally Sprayed Aluminum Oxide

1996 ◽  
Author(s):  
C.J. Swindeman ◽  
R.D. Seals ◽  
W.P. Murray ◽  
M.H. Cooper ◽  
R.L. White
Keyword(s):  
Electrical Properties ◽  
Aluminum Oxide ◽  
Dielectric Constants ◽  
Electrical Behavior ◽  
X Ray Diffraction ◽  
Heating And Cooling ◽  
Thermally Sprayed Aluminum ◽  
Plasma Sprayed ◽  
And Control ◽  
Steel Substrates

Abstract Electrical properties of plasma-sprayed aluminum oxide coatings were measured at temperatures up to 600 °C. High purity (&gt;99.5 wt% pure Al2O3) alumina powders were plasma-sprayed on stainless steel substrates over a range of power levels, using two gun configurations designed to attain different spray velocities. Key electrical properties were measured to evaluate the resultant coatings as potential insulating materials for electrostatic chucks (ESCs) being developed for semiconductor manufacturing. Electrical resistivity of all coatings was measured under vacuum upon heating and cooling over a temperature range of 20 to 600 °C. Dielectric constants were also measured under the same test conditions. X-ray diffraction was performed to examine phase formation in the coatings. Results show the importance of powder composition and careful selection and control of spray conditions for optimizing electrical behavior in plasma-sprayed aluminum oxide, and point to the need for further studies to characterize the relationship between high temperature electrical properties, measured plasma-spray variables, and specific microstructural and compositional coating features.

A Reusable 3D Printed Cavity Resonator for Liquid Sample Characterization

2018 ◽  
Vol 2018 (1) ◽  
pp. 000389-000392
Author(s):  
Saranraj Karuppuswami ◽  
Saikat Mondal ◽  
Mohd Ifwat Mohd Ghazali ◽  
Premjeet Chahal
Keyword(s):  
Dielectric Constant ◽  
Cavity Resonator ◽  
Dielectric Constants ◽  
Sample Holder ◽  
Strongly Coupled ◽  
Weakly Coupled ◽  
Sample Characterization ◽  
3D Printed ◽  
Standard Values ◽  
High Dielectric

Abstract In this paper, additive manufacturing (3D printing) is used to fabricate and demonstrate a reusable microfluidic coupled rectangular cavity resonator for characterizing liquids in small volumes. The designed cavity operates in the fundamental TE101 mode and resonates at 4.12 GHz. The resonance of the cavity is perturbed by the sample placed in a small volume sample holder through a slot in the top cover. Two different perturbation configurations are investigated: i) strongly coupled (liquids with low to medium dielectric constants), and ii) weakly coupled (liquids with medium to high dielectric constant). The sample holder is loaded with different solvents and the shift in the resonance frequency is monitored. Based on these changes, the dielectric constant of the solvent is theoretically estimated and compared to standard values. The reusable liquid sensor holds significant potential in identifying and quantifying unknown liquid samples in the supply chain.

Development of High-Dielectric-Strength Ceramic Film Capacitors for Advanced Power Electronics

2012 ◽  
Vol 2012 (1) ◽  
pp. 000609-000616
Author(s):  
Beihai Ma ◽  
Manoj Narayanan ◽  
Shanshan Liu ◽  
Sheng Tong ◽  
U. (Balu) Balachandran
Keyword(s):  
Dielectric Constant ◽  
Power Electronics ◽  
Room Temperature ◽  
Breakdown Strength ◽  
Dielectric Strength ◽  
X Ray Diffraction ◽  
Lead Lanthanum Zirconate Titanate ◽  
Solution Deposition ◽  
Ceramic Film ◽  
High Dielectric

Ceramic film capacitors with high dielectric constant and high breakdown strength are promising for use in advanced power electronics, which would offer higher performance, improved reliability, and enhanced volumetric and gravimetric efficiencies. We have grown lead lanthanum zirconate titanate (PLZT) on nickel foils and platinized silicon (PtSi) substrates by chemical solution deposition. A buffer layer of LaNiO3 (LNO) was deposited on the nickel foils prior to the deposition of PLZT. We measured the following electrical properties for PLZT films grown on LNO buffered Ni and PtSi substrates, respectively: remanent polarization, ≈25.4 μC/cm2 and ≈10.1 μC/cm2; coercive electric field, ≈23.8 kV/cm and ≈27.9 kV/cm; dielectric constant at room temperature, ≈1300 and ≈1350; and dielectric loss at room temperature, ≈0.06 and ≈0.05. Weibull analysis determined the mean breakdown strength to be 2.6 MV/cm and 1.5 MV/cm for PLZT films grown on LNO buffered Ni and PtSi substrates, respectively. Residual stress analysis by x-ray diffraction revealed compressive stress of ≈-520 MPa in the ≈2-μm-thick PLZT grown on LNO buffered Ni foil, but a tensile stress of ≈210 MPa in the ≈2-μm-thick PLZT grown on PtSi substrates.

Electrical Extraction of The in-Plane Dielectric Constant of Fluorinated Polyimide

1997 ◽  
Vol 476 ◽  
Author(s):  
Alvin L.S. Loke ◽  
Jeffrey T. Wetzel ◽  
John J. Stankus ◽  
S. Simon Wong
Keyword(s):  
Dielectric Constant ◽  
Electric Fields ◽  
Signal Propagation ◽  
Propagation Delay ◽  
Dielectric Constants ◽  
Effective Dielectric Constant ◽  
Fluorinated Polyimide ◽  
Lower Dielectric Constant ◽  
Out Of Plane ◽  
Fringing Fields

AbstractFluorinated polyimide can potentially replace TEOS as an interlevel dielectric in future ULSI interconnect technologies because its lower dielectric constant offers reduced crosstalk, signal propagation delay, and dynamic power dissipation. One issue associated with polyimides is the anisotropy in dielectric constant, where the smaller out-of-plane dielectric constant, typically measured using parallel-plate capacitors, can misleadingly exaggerate the advantage in reducing crosstalk. In this paper, we present a novel electrical technique to estimate the in-plane dielectric constant of DuPont FPI-136M fluorinated polyimide without requiring dielectric gapfill.A blanket FPI-136M film is deposited over interdigitated inlaid Al(0.5%Cu) structures and the crosstalk capacitance is measured. Identical inlaid structures with air and TEOS passivations are also measured for capacitance calibration. Differences in measured capacitances reflect electric fields fringing in the various passivation dielectrics above the inlaid metal. With the known dielectric constants of air and TEOS, the effective dielectric constant of FPI-136M is interpolated to be 2.8. Interconnect simulations confirm that the effective dielectric constant extraction technique is valid and accurate provided that the passivation layer is sufficiently thick to contain the fringing fields.To estimate the in-plane dielectric constant, we use simulations to determine the combination of in-plane and out-of-plane dielectric constants that is equivalent to the extracted effective dielectric constant. With an out-of-plane dielectric constant of 2.6, the in-plane dielectric constant of FPI-136M is estimated to be 3.0. This technique is applicable to other dieletrics.

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