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

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.

A novel functional polyurethane as a dielectric layer for organic thin-film transistors

2018 ◽  
Vol 42 (13) ◽  
pp. 10969-10975
Author(s):  
Xuesong Wang ◽  
He Wang ◽  
Yao Li ◽  
Ting Xu ◽  
Wei Wang ◽  
...  
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Layer ◽  
Thin Film Transistors ◽  
High Dielectric Constant ◽  
Organic Thin Film Transistors ◽  
Organic Thin Film ◽  
High Dielectric

A polyurethane material with a high dielectric constant was used to regulate the grain size of p-6P.

Effect of Platinum Substitution on the Microstructures and Dielectric Relaxation of CaCu3Ti4O12 Ceramics

2013 ◽  
Vol 802 ◽  
pp. 134-138 ◽  
Author(s):  
Worawut Makcharoen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Tangent ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Materials ◽  
X Ray Diffraction ◽  
High Loss ◽  
Internal Barrier Layer Capacitor ◽  
High Dielectric

The CaCu3Ti4O12(CCTO) has the advantage for the various applications especially for capacitive elements in microelectronic devices over the ferroelectric materials including BaTiO3. CCTO is a ceramic compound with a high dielectric constant but it has a high loss tangent at room temperature. In this work, the Influences of PtO2doping on the dielectric properties of CaCu3Ti4O12(CCTO) ceramics were investigate. The ceramics CCTO and PtO2doping CCTO were studied by X- ray diffraction, scanning electron microscopy. The dielectric properties have been measured as a function of temperature and frequency range 0.1 - 500 kHz. The XRD shows the CCTO structure does not changes after doping with platinum. The results show that PtO2doped can reduce the mean grain sizes of CCTO, but the dielectric constant still remained a height. The samples of 2.0 mol% Pt-doped have exhibited high dielectric constant of about 22,000 and the loss tangent about 0.7 at room temperature and frequency at 10 kHz. The reduced of the loss tangent could be interpreted with the internal barrier layer capacitor model (IBLC)

Very Thin Films of High Dielectric Constant Materials

1996 ◽  
Vol 446 ◽  
Author(s):  
David B. Beach ◽  
Catherine E. Vallet ◽  
Mariappan Paranthaman
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Layer ◽  
Single Phase ◽  
Annealing Temperature ◽  
Bismuth Titanate ◽  
High Dielectric Constant ◽  
Electrical Measurements ◽  
High Dielectric ◽  
Alkoxide Route

AbstractAn all‐alkoxide route to SrBi2Ta2O9 (SBT) thin films and powders was developed. While stoichiometric gels transformed to single‐phase SBT, excess bismuth was required to obtain single‐phase SBT films on Pt substrates. An annealing temperature of 800 °C in O2 for 2 minutes was required to crystallize the films. Electrical measurements of SBT films produced under these conditions showed that films less than 2000 Å in thickness were shorted, while films of 3000 to 5000 Λ had a dielectric constant of~ 300. RBS measurements of a bismuth titanate film on Pt indicated that Pt diffuses into the dielectric layer when annealed at 700 °C in O2 for 1 minute, suggesting that interfacial reaction of these layered bismuth materials may be significant.

scholarly journals Investigation of Grain Size Effect on the Impedance of CaCu3Ti4O12 from 100 Hz to 1 GHz of Frequency

2012 ◽  
Vol 620 ◽  
pp. 230-235 ◽  
Author(s):  
Muhammad Azwadi Sulaiman ◽  
Sabar Derita Hutagalung ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain
Keyword(s):  
Dielectric Constant ◽  
Barrier Layer ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Perovskite Phase ◽  
Wide Frequency Range ◽  
Treatment Temperature ◽  
Domain Boundaries ◽  
High Dielectric ◽  
Very High

CaCu3Ti4O12(CCTO) is a cubical perovskite phase and sintered ceramics exhibit very high dielectric constant at room temperature. The speculated origins of the high dielectric constant are the existence of insulative barrier layer at grain boundaries and domain boundaries which created an internal barrier layer capacitance (IBLC) at the microstructure of CCTO. The relation of grains and domains electrical resistance were studied in this work by using impedance spectroscopy (IS). A series of samples with different heat treatment temperature were tested to investigate their microstructure by using field emission scanning electron microscopy (FESEM). The grains and domains resistance was calculated from a wide frequency range of impedance complex plane measurement (100 Hz to 1 GHz). The FESEM and IS analyses showed the dependency of grains and domains resistance to average grains size of CCTO microstructure.

scholarly journals Cu(i) substituted wurtzite ZnO: a novel room temperature lead free ferroelectric and high-κ giant dielectric

RSC Advances ◽  
2020 ◽  
Vol 10 (19) ◽  
pp. 11382-11392 ◽  
Author(s):  
Neeraj Singh ◽  
Preetam Singh
Keyword(s):  
Dielectric Constant ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Lead Free ◽  
Giant Dielectric ◽  
High Dielectric

Cu+ ion substituted ZnO, Zn1−xCuxO1−δ have shown high dielectric constant (∼6300) at 600 °C at 100 kHz frequency and ferroelectricity at room temperature than for bulk Zn0.95Cu0.05O1−δ samples.

Dielectric and Ferroelectric Properties of BaTi1-xSnxO3 Multilayered Ceramics

2007 ◽  
Vol 555 ◽  
pp. 249-254 ◽  
Author(s):  
S. Marković ◽  
M. Mitrić ◽  
Č. Jovalekić ◽  
M. Miljković
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Properties ◽  
X Ray ◽  
High Dielectric ◽  
Scanning Electron

Multilayered BaTi1-xSnxO3 (BTS) ceramics with different Ti/Sn ratios were produced by pressing and sintering at 1420 oC for 2 hours. X-ray diffractometry, scanning electron microscopy and energy dispersive spectroscopy were used for structural, microstructural and elemental analysis, respectively. The dielectric and ferroelectric behavior of sintered samples was studied, too. It is found that in ingredient materials, with increasing Sn content, the tetragonality decreases; Curie temperature moves towards room temperature, while the maximum of the dielectric constant increases, and also, they becomes less hysteretic. It is noticed that multilayered BTS ceramics with different Ti/Sn contents have a broad transition temperature and show a relatively high dielectric constant in a wide temperature range. It is shown that dielectric properties of these materials may be modified by a combination of different BTS powders as well as layers number.

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

2020 ◽  
Vol 49 (7) ◽  
pp. 2218-2224 ◽  
Author(s):  
Siqian Chai ◽  
Jianbo Xiong ◽  
Yongshen Zheng ◽  
Rongchao Shi ◽  
Jialiang Xu
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Low Dielectric Constant ◽  
Dielectric Phase ◽  
Low Dielectric ◽  
High Dielectric

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.

scholarly journals A Composite of (95%) La2CoMnO6+ (5%) Ba0.5Na0.5TiO3 : Study of Structural and Dielectric Properties

2021 ◽  
Vol 2070 (1) ◽  
pp. 012093
Author(s):  
Dharmendra Mewada ◽  
Rajesh Kumar Katare
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Project Work ◽  
X Ray Diffraction ◽  
X Ray ◽  
Frequency Independent ◽  
Diffraction Peaks ◽  
High Dielectric

Abstract This project work reports synthesis, structural and dielectric nature of composite of the type (95%) La2CoMnO6+ (5%) Ba0.5Na0.5TiO3. The composite was characterized at room temperature for structural and dielectric properties. The structural characterization X-ray diffraction was carried for structural confirmation. The XRD data study convey the sample is dual phase in nature evident from the corresponding diffraction peaks. Monoclinic phase was acquired by La2CoMnO6 and the space groupof the phase is P 1 21/n whereas Ba0.5Na0.5TiO3 phase has acquired cubic structure with space group Pm-3m. The frequency dependent dielectric constant examined reveals high dielectric constant which decreases with increase in applied ac field values. Dielectric loss calculated shows the behaviour like dielectric constant which initially decreases abruptly with applied field and later attains frequency independent values. However, the ac conductivity was observed higher in the as synthesized.

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