New Perovskite Nanomaterials and Their Integrations into High-k Dielectrics

We report on a bottom-up manufacturing for high-k dielectric films using a novel nanomaterial, namely, a perovskite nanosheet (LaNb2O7) derived from a layered perovskite by exfoliation. Solution-based layer-by-layer assembly of perovskite nanosheets is effective for room-temperature fabrication of high-k nanocapacitors, which are directly assembled on a SrRuO3 bottom electrode with an atomically sharp interface. These nanocapacitors exhibit high dielectric constants (k > 50) for thickness down to 5 nm while eliminating problems resulting from the size effect. We also investigate dielectric properties of perovskite nanosheets with different compositions (LaNb2O7, La0.95Eu0.05Nb2O7, and Eu0.56Ta2O7) in order to study the influence of A- and B-site modifications on dielectric properties.

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Structural and Dielectric Properties of BaTi1-xSnxO3 Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.518.241 ◽

2006 ◽

Vol 518 ◽

pp. 241-246 ◽

Cited By ~ 9

Author(s):

S. Marković ◽

M. Mitrić ◽

N. Cvjetićanin ◽

Dragan P. Uskokovic

Keyword(s):

Dielectric Properties ◽

Room Temperature ◽

Dielectric Constants ◽

X Ray Diffraction ◽

Solid State Reaction Technique ◽

X Ray ◽

Low Dielectric ◽

High Dielectric ◽

Tin Content

BaTi1-xSnxO3 (BTS) powders, with x ranging from 0 to 1, were synthesized by solid-state reaction technique. The powders were pressed into pellets and sintered at 1370 and 1420 oC. The structural characterization of sintered BTS samples was made at room temperature using X-ray diffraction and Raman spectroscopy measurements. The BTS samples were found to be singlephase solid solutions. Dielectric properties of sintered BTS samples were studied as a function of sintering temperatures and tin contents, too. For samples with x ranging from 0 up to 0.15, it has been found that the Curie temperature decreases while the maximum of the dielectric constant increases with increasing tin content. These samples have relatively high dielectric constants, contrary to x > 0.2 samples with very low dielectric constants. It is noticed that BTS ceramics sintered at 1420 oC exhibit better dielectric properties than those sintered at 1370 oC.

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Electron microscopy studies of PZT ferroelectric film capacitor structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131450 ◽

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.

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ELECTRODELESS MEASUREMENT TECHNIQUE OF COMPLEX DIELECTRIC PERMITTIVITY OF HIGH-K DIELECTRIC FILMS IN THE MILLIMETER WAVELENGTH RANGE

Progress In Electromagnetics Research M ◽

10.2528/pierm16100505 ◽

2016 ◽

Vol 52 ◽

pp. 161-167 ◽

Cited By ~ 1

Author(s):

Igor V. Kotelnikov ◽

Andrey G. Altynnikov ◽

Anatoly Konstantinovich Mikhailov ◽

Valentina V. Medvedeva ◽

Andrey Kozyrev

Keyword(s):

Dielectric Permittivity ◽

Wavelength Range ◽

Measurement Technique ◽

Complex Dielectric Permittivity ◽

Dielectric Films ◽

Millimeter Wavelength ◽

High K ◽

High K Dielectric

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Epitaxial Growth and Anisotropic Dielectric Properties of La-Doped Bi4Ti3O12 Thin Films

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.177 ◽

2007 ◽

Vol 124-126 ◽

pp. 177-180

Author(s):

Jang Sik Lee ◽

Q.X. Jia

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Dielectric Properties ◽

Bottom Electrode ◽

Dielectric Constants ◽

The Other ◽

Field Range ◽

Anisotropic Dielectric ◽

Dielectric Nonlinearity ◽

La Doped

To investigate the anisotropic dielectric properties of layer-structured bismuth-based ferroelectrics along different crystal directions, we fabricate devices along different crystal orientations using highly c-axis oriented Bi3.25La0.75Ti3O12 (BLT) thin films on (001) LaAlO3 (LAO) substrates. Experimental results have shown that the dielectric properties of the BLT films are highly anisotropic along different crystal directions. The dielectric constants (1MHz at 300 K) are 358 and 160 along [100] and [110], respectively. Dielectric nonlinearity is also detected along these crystal directions. On the other hand, a much smaller dielectric constant and no detectable dielectric nonlinearity in a field range of 0-200 kV/cm are observed for films along [001] when c-axis oriented SRO is used as the bottom electrode.

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Modelling the Deposition of High-k Dielectric Films by First Principles

Journal of Electroceramics ◽

10.1007/s10832-004-5086-y ◽

2004 ◽

Vol 13 (1-3) ◽

pp. 117-120 ◽

Cited By ~ 16

Author(s):

Simon D. Elliott ◽

Henry P. Pinto

Keyword(s):

First Principles ◽

Dielectric Films ◽

High K ◽

High K Dielectric

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Microstructure and Dielectric Properties of LixTixNi1-2xO Thin Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.1817 ◽

2008 ◽

Vol 368-372 ◽

pp. 1817-1819

Author(s):

Cui Hua Zhao ◽

Bo Ping Zhang ◽

Yong Liu ◽

Song Jie Li

Keyword(s):

Thin Films ◽

Dielectric Properties ◽

Spin Coating ◽

Sol Gel ◽

Dielectric Constants ◽

Co Doping ◽

Grain Sizes ◽

Uniform Microstructure ◽

Coating Method ◽

High Dielectric

LixTixNi1-2xO (x =0, 10 and 20 at. %) thin films with 200 nm in thickness were deposited on Pt/Ti/SiO2/Si (100) by a sol-gel spin-coating method. All samples have a uniform microstructure. The grain sizes grew from 100 nm to 300 nm by co-doping Li and Ti. The LiTiNiO thin films consist of NiO, NiTiO3 and Li2NiO2, while the Li-free thin films consist of NiO, NiTiO3 and NiTi0.99O3. The dielectric properties of the LiTiNiO thin films improved obviously by co-doping Li and Ti, but excess Li increases the amount of Li2NiO2 phase and decreases the dielectric properties. The dielectric constants at 100 Hz for the Li0.1Ti0.1Ni0.8O and Li0.2Ti0.2Ni0.6O thin films are 506 and 388 respectively. Appropriate co-doping contents of Li and Ti are important to obtain a high dielectric property.

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High-K dielectric sulfur-selenium alloys

Science Advances ◽

10.1126/sciadv.aau9785 ◽

2019 ◽

Vol 5 (5) ◽

pp. eaau9785 ◽

Cited By ~ 3

Author(s):

Sandhya Susarla ◽

Thierry Tsafack ◽

Peter Samora Owuor ◽

Anand B. Puthirath ◽

Jordan A. Hachtel ◽

...

Keyword(s):

Dielectric Constant ◽

Metal Oxides ◽

High Dielectric Constant ◽

Dielectric Material ◽

Dielectric Strength ◽

Dielectric Materials ◽

High K ◽

Device Applications ◽

High K Dielectric ◽

High Dielectric

Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications.

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Structural and dielectric properties of Bi2NbxVi−xO5.5 ceramics

Journal of Materials Research ◽

10.1557/jmr.1996.0291 ◽

1996 ◽

Vol 11 (9) ◽

pp. 2288-2292 ◽

Cited By ~ 14

Author(s):

K. B. R. Varma ◽

K. V. R. Prasad

Keyword(s):

Differential Scanning Calorimetry ◽

Grain Size ◽

Dielectric Properties ◽

Curie Temperature ◽

Room Temperature ◽

Dielectric Constants ◽

Scanning Calorimetry ◽

Electron Microscopic ◽

Scanning Electron Microscopic ◽

Scanning Electron

Bi2Nbx V1−xO5.5 ceramics with x ranging from 0.01 to 0.5 have been prepared. The crystal system transforms from an orthorhombic to tetragonal at x 3= 0.1 and it persists until x = 0.5. Scanning electron microscopic (SEM) investigations carried out on thermally etched Bi2NbxV1−xO5.5 ceramics confirm that the grain size decreases markedly (18 μm to 4 μm) with increasing x. The shift in the Curie temperature (725 K) toward lower temperatures, with increasing x, is established by Differential Scanning Calorimetry (DSC). The dielectric constants as well as the loss tangent (tan δ) decrease with increasing x at room temperature.

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HIGH DIELECTRIC PROPERTIES OF LOW-TEMPERATURE SINTERED (Ca0.5Cu0.5)TiO3 CERAMICS

Journal of Advanced Dielectrics ◽

10.1142/s2010135x11000197 ◽

2011 ◽

Vol 01 (02) ◽

pp. 203-207 ◽

Cited By ~ 2

Author(s):

JIAN-CONG YUAN ◽

YUAN-HUA LIN ◽

BO CHENG ◽

CE-WEN NAN

Keyword(s):

Dielectric Properties ◽

Sintering Temperature ◽

Sol Gel ◽

Impedance Spectrum ◽

Dielectric Constants ◽

Sintering Process ◽

Remarkable Effect ◽

High Dielectric Permittivity ◽

Wide Range ◽

High Dielectric

High dielectric-permittivity ( Ca0.5Cu0.5)TiO3 -based ceramics have been prepared by a sol-gel method combined with a solid state sintering process. The results indicate that the additives of H3BO3 have a remarkable effect on the sintering temperature, microstructure and dielectric properties. High density ( Ca0.5Cu0.5)TiO3 bulk ceramics can be obtained after sintering at 900°C. The as-sintered ceramics show high dielectric constants (~1000), and low losses (~0.05). The dielectric properties are nearly independent of frequency and temperature in a wide range. The activation energy is calculated as about 0.50 eV by impedance spectrum method.

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