Dielectric phase transition of an A2BX4-type perovskite with a pentahedral to octahedral transformation

The as-synthesized 2D perovskite [C5H12N]2PbCl4 undergoes an above-room-temperature dielectric phase transition with a reversible pentahedral to octahedron transformation and a high dielectric constant being over twice of the low dielectric constant.

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Pulsed DC Magnetron Sputtered Rutile TiO2 films for next generation DRAM capacitors

MRS Proceedings ◽

10.1557/opl.2013.823 ◽

2013 ◽

Vol 1561 ◽

Author(s):

M.A Jithin ◽

Lakshmi Ganapathi Kolla ◽

Navakanta Bhat ◽

S. Mohan ◽

Yuichiro Morozumi ◽

...

Keyword(s):

Dielectric Constant ◽

High Dielectric Constant ◽

Low Dielectric Constant ◽

Si Substrate ◽

Capacitance Density ◽

Low Dielectric ◽

Pulsed Dc ◽

High Dielectric ◽

Mim Capacitors

ABSTRACTIn this study, synthesis and characterization of rutile-Titanium dioxide (TiO2) thin films using pulsed DC Magnetron Sputtering at room temperature, along with the fabrication and characterization of MIM capacitors have been discussed. XPS and RBS data show that the films are stoichiometric and have compositional uniformity. The influence of electrode materials on electrical characteristics of the fabricated MIM capacitors has been studied. The Al/TiO2/Al based capacitors show low capacitance density (9 fF/μm2) with low dielectric constant (K=25) and high EOT (3.67 nm) due to low dielectric constant TiO2 phase formation on Al/Si substrate. On the other hand, Ru/TiO2/Ru based capacitors show high capacitance density (49 fF/μm2) with high dielectric constant (K=130) and low EOT (0.7nm) values at high frequency (100 KHz) due to high dielectric constant phase (rutile) formation of TiO2, on Ru/Si substrate. Raman spectra confirm that the films deposited on Ru/Si substrate show the rutile phase.

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Magnetic nonequivalence in asymmetric phosphorus compounds

Canadian Journal of Chemistry ◽

10.1139/v69-522 ◽

1969 ◽

Vol 47 (17) ◽

pp. 3167-3171 ◽

Cited By ~ 5

Author(s):

L. Frankel ◽

J. Cargioli ◽

H. Klapper ◽

R. Danielson

Keyword(s):

Nuclear Magnetic Resonance ◽

Dielectric Constant ◽

Magnetic Resonance ◽

Chemical Shift ◽

High Dielectric Constant ◽

Phosphorus Compounds ◽

Low Dielectric Constant ◽

Methyl Groups ◽

Low Dielectric ◽

High Dielectric

The nuclear magnetic resonance (n.m.r.) spectra of seven compounds of the type (CH3)P(O)(SCH2SR)(OR′) have been examined as a function of solvent. The resonance pattern of the methylene protons, SCH2S, is strongly solvent dependent. In solvents of low dielectric constant, the methylene protons are magnetically nonequivalent and are observed as the AB part of an ABX spin system, where X is the phosphorus atom. In high dielectric constant medium (DMSO d6) only a well-resolved doublet is obtained indicating magnetic equivalence. When R′ = CH(CH3)2, nonequivalent methyl groups which show analogous solvent effects are observed.Eight compounds of the type (CH3)P(O)(OCH(CH3)2)(X) have been studied. The chemical shift between the magnetically nonequivalent isopropyl methyl groups does not correlate with any simple property of X.

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Conformational studies of peptides corresponding to the coeliac-activating regions of wheat α-gliadin

Biochemical Journal ◽

10.1042/bj2700313 ◽

1990 ◽

Vol 270 (2) ◽

pp. 313-318 ◽

Cited By ~ 43

Author(s):

A S Tatham ◽

M N Marsh ◽

H Wieser ◽

P R Shewry

Keyword(s):

Dielectric Constant ◽

Structure Prediction ◽

High Dielectric Constant ◽

Protein A ◽

Active Regions ◽

Low Dielectric Constant ◽

Type I ◽

Terminal Part ◽

Low Dielectric ◽

High Dielectric

The structures of four peptides corresponding to parts of the coeliac-activating protein A-gliadin were studied by structure prediction and c.d. spectroscopy. Three of the peptides corresponded to parts of the coeliac-activating N-terminal region (residues 3-55, 3-19 and 39-45) and contained two tetrapeptide motifs common to all coeliac-active regions (Pro-Ser-Gln-Gln and Gln-Gln-Gln-Pro). The Pro-Ser-Gln-Gln sequence was also present in the fourth peptide, on the basis of the C-terminal part of the molecule (211-217). These studies showed that beta-reverse turns were the predominant structural feature in all peptides and were predominantly of type I/III in two of the N-terminal peptides and type II in the C-terminal peptide. These turns form when the peptide is dissolved in solvents of low dielectric constant (trifluoroethanol) and high dielectric constant (water and iso-osmotic saline), although their presence in the N-terminal peptides may be masked in the latter solvents due to equilibrium with a poly-L-proline II structure favoured at lower temperatures.

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High and Low Dielectric Constant Materials

The Electrochemical Society Interface ◽

10.1149/2.f06992if ◽

1999 ◽

Vol 8 (2) ◽

pp. 26-30

Author(s):

Rajenda Singh ◽

Richard K. Ulrich

Keyword(s):

Dielectric Constant ◽

Integrated Circuits ◽

High Dielectric Constant ◽

Low Dielectric Constant ◽

Low Dielectric ◽

A Value ◽

Silicon Integrated Circuits ◽

Low Dielectric Constant Materials ◽

High Dielectric ◽

Silicon Based

Silicon-based dielectrics (SiO2, Si3N4, SiOxNy etc.) have been widely used as the key dielectrics in the manufacturing of silicon integrated circuits (ICs) and virtually all other semiconductor devices. Dielectrics having a value of dielectric constant k × 8.854 F/cm more than that of silicon nitride (k > 7) are classified as high dielectric constant materials, while those with a value of k less than the dielectric constant of silicon dioxide (k < 3.9) are classified as the low dielectric constant materials. The minimum value of (k) is one for air. The highest value of k has been reported for relaxor ferroelectric (k = 24,700 at 1 kHz).

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Influence of high and low dielectric constant plasticizers on the ion transport properties of PEO: NH4HF2 polymer electrolytes

High Performance Polymers ◽

10.1177/0954008319894043 ◽

2020 ◽

Vol 32 (2) ◽

pp. 142-150 ◽

Cited By ~ 2

Author(s):

Jitender Paul Sharma ◽

Vijay Singh

Keyword(s):

Dielectric Constant ◽

Ionic Conductivity ◽

Ion Transport ◽

Transport Properties ◽

Polymer Electrolytes ◽

High Dielectric Constant ◽

Low Dielectric Constant ◽

Low Dielectric ◽

Amorphous Nature ◽

High Dielectric

Different composition ratio of polymer electrolytes based on poly(ethylene oxide) (PEO) as host polymer, ammonium bifluoride (NH4HF2) as salt, and propylene carbonate (PC), dimethyl acetamide (DMA), dimethyl chloride (DMC), and diethyl carbonate (DEC) as plasticizers has been prepared by solution casting technique. The influence of high dielectric constant plasticizers (PC and DMA) and low dielectric constant plasticizers (DMC and DEC) on the ion transport properties of PEO-NH4HF2 polymer electrolytes has been studied. The increase in ionic conductivity of polymer electrolytes containing PC and DMA is observed to be more as compared to those electrolytes containing DMC and DEC, which is due to an increase in both the amorphous phase and dielectric constant of PEO. X-ray diffraction study reveals the amorphous nature in case of plasticized polymer electrolyte. In the Fourier transform infrared study, the changes and shifting of the different characteristic peaks confirm the polymer–salt complex formation and the dissociation of ion aggregates present at higher concentration of salt with the addition of PC. Maximum ionic conductivity of 1.40 × 10−4 S cm−1 at room temperature has observed in case of plasticized polymer electrolytes containing optimum concentration of PC so that mechanical stability and flexibility be maintained. The variation of linewidth with temperature has also been studied by 1H and 19F nuclear magnetic resonance (NMR), which confirms that both cations and anions are mobile in these polymer electrolytes. Line narrowing associated with the glass transition temperature ( T g; low mobility region) and melting temperature ( T m; high mobility region) of PEO has also been observed for plasticized polymer electrolytes containing PC having optimum conductivity value. Conductivity versus temperature variation study reveals curved nature of plot in case of plasticized polymer electrolytes containing high dielectric constant plasticizers, which is significant for their amorphous nature. Smooth morphology observed in case of plasticized polymer electrolytes having optimum conductivity value is essential key factor for polymer electrolytes to be suitable for practical applications.

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Skin–core structured fluorinated MWCNTs: a nanofiller towards a broadband dielectric material with a high dielectric constant and low dielectric loss

Journal of Materials Chemistry C ◽

10.1039/c7tc05434c ◽

2018 ◽

Vol 6 (9) ◽

pp. 2370-2378 ◽

Cited By ~ 11

Author(s):

Yang Liu ◽

Cheng Zhang ◽

Benyuan Huang ◽

Xu Wang ◽

Yulong Li ◽

...

Keyword(s):

Dielectric Constant ◽

Dielectric Loss ◽

High Dielectric Constant ◽

Dielectric Material ◽

Epoxy Composite ◽

Low Dielectric ◽

High Dielectric

A novel skin–core structured fluorinated MWCNT nanofiller was prepared to fabricate epoxy composite with broadband high dielectric constant and low dielectric loss.

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Atomistic prediction on the configuration- and temperature-dependent dielectric constant of Be0.25Mg0.75O superlattice as a high-κ dielectric layer

Journal of Materials Chemistry C ◽

10.1039/d0tc05071g ◽

2021 ◽

Author(s):

Gyuseung Han ◽

In Won Yeu ◽

Kun Hee Ye ◽

Seung-Cheol Lee ◽

Cheol Seong Hwang ◽

...

Keyword(s):

Dielectric Constant ◽

Dft Calculations ◽

Bond Length ◽

Dielectric Layer ◽

Room Temperature ◽

High Dielectric Constant ◽

Temperature Dependent ◽

High Dielectric

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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