Switching Dielectric Constant Near Room Temperature in a Molecular Crystal

Through DFT calculations, a Be0.25Mg0.75O superlattice having long apical Be–O bond length is proposed to have a high bandgap (>7.3 eV) and high dielectric constant (∼18) at room temperature and above.

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Synthesis and electrical characterization of Ca2Nd4Ti6O20 ceramics

Materials Science-Poland ◽

10.1515/msp-2016-0021 ◽

2016 ◽

Vol 34 (1) ◽

pp. 164-168

Author(s):

Raz Muhammad ◽

Muhammad Uzair ◽

M. Javid Iqbal ◽

M. Jawad Khan ◽

Yaseen Iqbal ◽

...

Keyword(s):

Activation Energy ◽

Dielectric Constant ◽

Room Temperature ◽

Sol Gel ◽

Electrical Characterization ◽

Sintered Sample ◽

First Time ◽

Alkoxide Precursors ◽

Room Temperature Dielectric Constant

AbstractCa2Nd4Ti6O20, a layered perov skite structured material was synthesized via a chemical (citrate sol-gel) route for the first time using nitrates and alkoxide precursors. Phase analysis of a sample sintered at 1625 °C revealed the formation of an orthorhombic (Pbn21) symmetry. The microstructure of the sample after sintering comprised rod-shaped grains of a size of 1.5 to 6.5µm. The room temperature dielectric constant of the sintered sample was 38 at 100 kHz. The remnant polarization (Pr) and the coercive field (Ec) were about 400 μC/cm2 and 8.4 kV/cm, respectively. Impedance spectroscopy revealed that the capacitance (13.7 pF) and activation energy (1.39 eV) of the grain boundary was greater than the capacitance (5.7 pF) and activation energy (1.13 eV) of the grain.

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Silk Polymer Coating with Low Dielectric Constant and High Thermal Stability for Ulsi Interlayer Dielectric

MRS Proceedings ◽

10.1557/proc-476-9 ◽

1997 ◽

Vol 476 ◽

Cited By ~ 46

Author(s):

P. H. Townsend ◽

S. J. Martin ◽

J. Godschalx ◽

D. R. Romer ◽

D. W. Smith ◽

...

Keyword(s):

Thin Film ◽

Dielectric Constant ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Integrated Circuits ◽

Room Temperature ◽

Polymer Network ◽

Flow Characteristics ◽

Interlayer Dielectric

AbstractA novel polymer has been developed for use as a thin film dielectric in the interconnect structure of high density integrated circuits. The coating is applied to the substrate as an oligomeric solution, SiLK*, using conventional spin coating equipment and produces highly uniform films after curing at 400 °C to 450 °C. The oligomeric solution, with a viscosity of ca. 30 cPs, is readily handled on standard thin film coating equipment. Polymerization does not require a catalyst. There is no water evolved during the polymerization. The resulting polymer network is an aromatic hydrocarbon with an isotropie structure and contains no fluorine.The properties of the cured films are designed to permit integration with current ILD processes. In particular, the rate of weight-loss during isothermal exposures at 450 °C is ca. 0.7 wt.%/hour. The dielectric constant of cured SiLK has been measured at 2.65. The refractive index in both the in-plane and out-of-plane directions is 1.63. The flow characteristics of SiLK lead to broad topographic planarization and permit the filling of gaps at least as narrow as 0.1 μm. The glass transition temperature for the fully cured film is greater than 490 °C. The coefficient of thermal expansivity is 66 ppm/°C below the glass transition temperature. The stress in fully cured films on Si wafers is ca. 60 MPa at room temperature. The fracture toughness measured on thin films is 0.62 MPa m ½. Thin coatings absorb less than 0.25 wt.% water when exposed to 80% relative humidity at room temperature.

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The effects of additive on microstructure and electrical properties of batio3 ceramics

Serbian Journal of Electrical Engineering ◽

10.2298/sjee0403089p ◽

2004 ◽

Vol 1 (3) ◽

pp. 89-98 ◽

Cited By ~ 16

Author(s):

Vesna Paunovic ◽

Ljiljana Zivkovic ◽

Ljubomir Vracar ◽

Vojislav Mitic ◽

Miroslav Miljkovic

Keyword(s):

Dielectric Constant ◽

Curie Temperature ◽

Room Temperature ◽

Low Frequency ◽

Dissipation Factor ◽

The Other ◽

Uniform Microstructure ◽

Average Grain Size ◽

Solid State Sintering ◽

Curie Temperatures

In this paper comparative investigations of microstructure and dielectric properties of BaTiO3 ceramics doped with 1.0 wt% of Nb2O5, MnCO3 and CaZrO3 have been done. BaTiO3 samples were prepared using conventional method of solid state sintering at 13000C for two hours. Two distinguish micro structural regions can be observed in sample doped with Nb2O5. The first one, with a very small grained microstructure and the other one, with a rod like grains. In MnCO3 and CaZrO3 doped ceramics the uniform microstructure is formed with average grain size about 0.5- 2?m and 3-5?m respectively. The highest value of dielectric permittivity at room temperature and the greatest change of permittivity in function of temperature were observed in MnCO3/BaTiO3. In all investigated samples dielectric constant after initially large value at low frequency attains a constant value at f = 6kHz. A dissipation factor is independent of frequency greater than 10 kHz and, depending of systems, lies in the range from 0.035 to 0.25. At temperatures above Curie temperatures, the permittivity of all investigated samples follows a Curie- Weiss law. A slight shift of Curie temperature to the lower temperatures, in respect of Curie temperature for undoped BaTiO3, was observed in all investigated samples.

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Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

Processing and Application of Ceramics ◽

10.2298/pac1603183a ◽

2016 ◽

Vol 10 (3) ◽

pp. 183-188 ◽

Cited By ~ 5

Author(s):

Mohamed Afqir ◽

Amina Tachafine ◽

Didier Fasquelle ◽

Mohamed Elaatmani ◽

Jean-Claude Carru ◽

...

Keyword(s):

Dielectric Constant ◽

Solid State ◽

Room Temperature ◽

Single Phase ◽

Solid State Reaction Method ◽

X Ray Diffraction ◽

Reaction Method ◽

X Ray ◽

Lcr Meter ◽

Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

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Pyroelectric Properties of the Plt(10) Thin Film on the P-Doped Poly Silicon

MRS Proceedings ◽

10.1557/proc-433-413 ◽

1996 ◽

Vol 433 ◽

Author(s):

Seong Jun Kang ◽

Yung Sup Yoon ◽

Dong Il Kim

Keyword(s):

Thin Film ◽

Dielectric Constant ◽

Curie Temperature ◽

Room Temperature ◽

Sol Gel ◽

Pyroelectric Coefficient ◽

Pyroelectric Properties ◽

Gel Method ◽

Sol Gel Method ◽

Poly Silicon

AbstractWe have studied the pyroelectric properties of the PLT(10) thin film deposited on a p-doped poly-Si electrode by using the sol-gel method. Measurement of the dielectric constant as a function of temperature shows the typical characteristics of a ferroelectric. The dielectric constant reaches a maximum at 295°C, which can be thought of as the Curie temperature. The PLT(10) thin film on p-doped poly-Si fabricated in this research shows excellent pyroelectric properties. The pyroelectric coefficient and the fiqures of merit, Fv and FD at room temperature are measured as 5.76 × 10−8 C/cm2 °C, 1.17 × 10−10C-cm/J and 0.93 × 10−8C-cm/J, respectively.

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

International Symposium on Microelectronics ◽

10.4071/isom-2012-wa33 ◽

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.

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Low-k Dielectric Obtained by Noble Gas Implantation in Silicon Oxide

MRS Proceedings ◽

10.1557/proc-0914-f03-04 ◽

2006 ◽

Vol 914 ◽

Cited By ~ 1

Author(s):

Hanan Assaf ◽

E. Ntsoenzok ◽

M-O. Ruault ◽

S. Ashok

Keyword(s):

Dielectric Constant ◽

Room Temperature ◽

Silicon Oxide ◽

Noble Gas ◽

Reference Sample ◽

Strong Decrease ◽

Capacitance Measurements ◽

Low K ◽

Higher Doses ◽

Very High

AbstractThermally-grown 220nm-thick silicon oxide layers were implanted at room temperature with 300keV Xe at doses ranging from 0.5 to 5x1016Xe/cm2. As-implanted samples exhibit bubbles in silicon oxide for all doses. Annealing at T≤400°C results in the disappearance of bubbles from SiO2 layer for the dose of 1x1016Xe/cm2. But for the higher doses of 3.5 and 5x1016Xe/cm2, the bubbles are very stable and remain in the sample even after very high thermal annealing. Capacitance measurements show a strong decrease in the dielectric constant k of the implanted SiO2 sample from 4 (reference sample) to 1.5.

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Dielectric properties and conductivity of PVdF-co-HFP/LiClO4 polymer electrolytes

Canadian Journal of Physics ◽

10.1139/cjp-2017-0678 ◽

2018 ◽

Vol 96 (7) ◽

pp. 786-791 ◽

Cited By ~ 1

Author(s):

Kemal Ulutaş ◽

Ugur Yahsi ◽

Hüseyin Deligöz ◽

Cumali Tav ◽

Serpil Yılmaztürk ◽

...

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Dielectric Loss ◽

Polymer Electrolytes ◽

Room Temperature ◽

Solid Polymer Electrolytes ◽

Solid Polymer ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Maximum Conductivity

In this study, it was aimed to prepare a series of PVdF-co-HFP based electrolytes with different LiClO4 loadings and to investigate their chemical and electrical properties in detail. For this purpose, PVdF-co-HFP based electrolytes with different LiClO4 loadings (1–20 weight %) were prepared using solution casting method. X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric (TGA) –differential thermal and dielectric spectroscopy analysis of PVdF-co-HFP/LiClO4 were performed to characterize their structural, thermal, and dielectric properties, respectively. XRD results showed that the diffraction peaks of PVdF-co-HFP/LiClO4 electrolytes broadened and decreased with LiClO4. TGA patterns exhibited that PVdF-co-HFP/LiClO4 electrolytes with 20 wt % of LiClO4 had the lowest thermal stability and it degraded above 473 K, which is highly applicable for solid polymer electrolytes. Dielectric constant, dielectric loss, and conductivities were calculated by measuring capacitance and dielectric loss factor of PVdF-co-HFP/LiClO4 in the range from 10 mHz to 20 MHz frequencies at room temperature. In consequence, conductivities of PVdF-co-HFP/LiClO4 increased significantly with frequency for low loading of LiClO4 while they only slightly changed with higher LiClO4 addition. On the other hand, dielectric constant values of PVdF-co-HFP/LiClO4 films decreased with frequency whereas they rose with LiClO4 addition. The dielectric studies showed an increase in dielectric constant and dielectric loss with decreasing frequency. This result was attributed to high contribution of charge accumulation at the electrode–electrolyte interface. The electrolyte showed the maximum conductivity of 8 × 10−2 S/cm at room temperature.

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