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

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.

Author(s):  
Gyuseung Han ◽  
In Won Yeu ◽  
Kun Hee Ye ◽  
Seung-Cheol Lee ◽  
Cheol Seong Hwang ◽  
...  

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.


2017 ◽  
Vol 43 (4) ◽  
pp. 3923-3926 ◽  
Author(s):  
Muhammad Nauman Khan ◽  
Nadeem Jelani ◽  
Chunchun Li ◽  
Jibran Khaliq

2013 ◽  
Vol 802 ◽  
pp. 134-138 ◽  
Author(s):  
Worawut Makcharoen

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)


2017 ◽  
Vol 866 ◽  
pp. 277-281
Author(s):  
Naphat Albutt ◽  
Suejit Pechprasarn ◽  
Pattaraporn Damkoengsuntorn ◽  
Thanapong Sareein

In this work, the uses of giant dielectric constant of Y2NiMnO6 ceramics were investigated in the frequency range from 1 kHz to 3 MHz. The Y2NiMnO6 ceramics were sintered at 1400 °C for 6, 12, 18 and 24 hours, respectively. The dielectric properties of Y2NiMnO6 ceramics were examined in dc bias from 0 to 1.5 volt at room temperature. We found that all sintering times displayed high dielectric permittivity at frequencies below 105 Hz, above which the values decreased significantly, applied dc bias also reduced dielectric permittivity. The peak of dielectric loss decreased significantly at high dc bias due to decreased contribution of dc conductivity in grain ceramics. This research has characterised electrical properties of Y2NiMnO6 ceramics which maybe suitable for electronic components including batteries and capacitors.


2012 ◽  
Vol 620 ◽  
pp. 230-235 ◽  
Author(s):  
Muhammad Azwadi Sulaiman ◽  
Sabar Derita Hutagalung ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain

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.


2007 ◽  
Vol 555 ◽  
pp. 249-254 ◽  
Author(s):  
S. Marković ◽  
M. Mitrić ◽  
Č. Jovalekić ◽  
M. Miljković

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.


2020 ◽  
Vol 49 (7) ◽  
pp. 2218-2224 ◽  
Author(s):  
Siqian Chai ◽  
Jianbo Xiong ◽  
Yongshen Zheng ◽  
Rongchao Shi ◽  
Jialiang Xu

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.


Sign in / Sign up

Export Citation Format

Share Document