High Piezoelectric Property and Low Dielectric Constant PZN-PZT Ceramics

2007 ◽  
pp. 7-9
Author(s):  
Dong Xiang Zhou ◽  
Yi Hua Deng ◽  
Shu Ping Gong ◽  
Bo Wu Yan ◽  
Zhi Qiang Zhuang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Piezoelectric Property ◽  
Low Dielectric Constant ◽  
Pzt Ceramics ◽  
Low Dielectric ◽  
High Piezoelectric Property

High Piezoelectric Property and Low Dielectric Constant PZN-PZT Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 7-9 ◽  
Author(s):  
Dong Xiang Zhou ◽  
Yi Hua Deng ◽  
Shu Ping Gong ◽  
Bo Wu Yan ◽  
Zhi Qiang Zhuang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Tetragonal Phase ◽  
Perovskite Structure ◽  
Relative Dielectric Constant ◽  
Rhombohedral Phase ◽  
Xrd Analysis ◽  
Low Dielectric Constant ◽  
Pzt Ceramics ◽  
Low Dielectric ◽  
High Piezoelectric Property

The influences of the substitution of (Zn1/3Nb2/3) group for Ti as well as addition of Fe2O3 and K2CO3 on d33, kp, εr, and tgδ of the Pb[Zr0.46Ti0.54-x(Zn1/3Nb2/3)x]O3 + y mol%Fe2O3+z mol%K2CO3 (PZNPZT) (0 ≤ x ≤ 0.20, 0 ≤ y ≤ 0.10, 0 ≤ z ≤ 0.20) ceramics were investigated. The experimental results demonstrated that when x increases in Pb[Zr0.46Ti0.54-x(Zn1/3Nb2/3)x]O3+0.3 mol%Fe2O3+0.5mol%K2CO3 ceramics, the d33, kp, εr, and tgδ increase and approach to their maximum values, then eventually decrease. XRD analysis revealed that the perovskite structure of the materials transfers from tetragonal phase to rhombohedral phase. The relative dielectric constant (εr) decreases dramatically in the rhombohedral phase area near the MPB; the d33 and εr decrease with the small amount of added Fe2O3 and K2CO3, which also contributes to densification of the PZN-PZT ceramics. The optimized piezoelectric performances through the experiment were obtained as d33=280 pC/N, kp=0.62, εr=900, tgδ=0.003.

Structire, Properties, and Process Characteristics of Low-K Materials Prepared by PECVD

1999 ◽  
Vol 565 ◽  
Author(s):  
Y. Shimogaki ◽  
S. W. Lim ◽  
E. G. Loh ◽  
Y. Nakano ◽  
K. Tada ◽  
...  
Keyword(s):  
Growth Rate ◽  
Dielectric Constant ◽  
Gas Flow ◽  
Structural Changes ◽  
Silicon Oxide ◽  
Reactive Species ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Step Coverage ◽  
Low K

AbstractLow dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.

Defect free monolayer and bilayer graphene exfoliated by solvent with low dielectric constant

2020 ◽  
Author(s):  
Vedanki ◽  
Chandrabhan Dohare ◽  
Pawan KumarSrivastava ◽  
Premlata Yadav ◽  
Subhasis Ghosh
Keyword(s):  
Dielectric Constant ◽  
Bilayer Graphene ◽  
Low Dielectric Constant ◽  
Low Dielectric
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