Effect of Neodymium and Samarium on the Properties of Bismuth Titanate Ceramics

2015 ◽  
Vol 761 ◽  
pp. 397-401
Author(s):  
Umar Al Amani Azlan ◽  
Ahmad Fauzi Mohd Noor ◽  
Yusliza Yusuf ◽  
Nooririnah Omar ◽  
Noraiham Mohamad
Keyword(s):  
Dielectric Constant ◽  
Single Phase ◽  
Bismuth Titanate ◽  
Pyrochlore Phase ◽  
Single Step ◽  
Phase Detection ◽  
Rare Earth Compounds ◽  
Low Dielectric ◽  
Calcination Step ◽  
Titanate Ceramics

This paper reported the doping effect on BIT by two different rare-earth compounds i.e. Nd and Sm, each at different mole content (0.25, 0.5, 0.75 and 1.0 mol). The so-called single-step combustion synthesis was used to produce the as-combusted powders, whereby the intermediate calcination step was then eliminated. This method was able to sinter the samples at temperature as low as 1000°C for 3 h. The entire ceramics were characterized for phase detection and stability, microstructure and dielectric properties. It was found that the single phase BIT was successfully formed with Nd and Sm doping. However, little content of pyrochlore phase was detected in the sample with Sm doping particularly at high mole content. (0.5 to 1.0 mol). Besides, a remarkable decrease in the grain size with better microstructure was observed particularly at high mole content (1.0). The improvement in microstructure led to the increase in dielectric constant with low dielectric loss.

Sol-Gel Derived Barium Sodium Niobate and Bismuth Titanate Films

1991 ◽  
Vol 243 ◽  
Author(s):  
J.M. Boulton ◽  
G. Teowee ◽  
W.M. Bomnersbach ◽  
D.R. Uhlmann
Keyword(s):  
Dielectric Constant ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Single Phase ◽  
Bismuth Titanate ◽  
Second Harmonic ◽  
Sol Gel ◽  
Sodium Niobate ◽  
Ethyl Hexanoate ◽  
Sputtered Films

AbstractSol-gel derived barium sodium niobate and bismuth titanate films were successfully prepared from precursor solutions of chelated Ba[Nb(OEt)6]2 and NaNb(OEt)6 and from bismuth 2-ethyl hexanoate and Ti(OEt)4 respectively. Single phase Ba2NaNb5O15 was formed at 750C on platinized Si and at 850C on fused SiO2. Monoclinic (pseudo-orthorhombic) Bi4Ti3O12 was formed at temperatures as low as 500C. Both film compositions showed significant second harmonic generation. The dielectric constant of the bismuth titanate film was comparable to that of sputtered films.

Electrical Characterization of Sol-Gel Derived PZT Films

1991 ◽  
Vol 243 ◽  
Author(s):  
G. Teowee ◽  
J.M. Boulton ◽  
S.C. Lee ◽  
D.R. Uhlmann
Keyword(s):  
Dielectric Constant ◽  
Low Temperatures ◽  
Lead Acetate ◽  
Single Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Electrical Characterization ◽  
Aging Rate ◽  
Pzt Films

AbstractSol-gel derived PZT films were successfully prepared from precursor solutions based on lead acetate and Zr/Ti alkoxides. A pyrochlore phase was observed in films fired at low temperatures, while single-phase perovskite films were obtained at temperatures above 725C. The dielectric constant increased to above 1000 when there was a higher proportion of perovskite than pyrochlore. The films were essentially fatigue-free up to 108 cycles and exhibited a low aging rate of 5.7% / decade-sec.

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 Structure and dielectric properties of (1-x)Bi 0.5 Na 0.5 TiO 3–x BaTiO 3 piezoceramics prepared using hydrothermally synthesized powders

2021 ◽  
Vol 8 (7) ◽  
pp. 202365
Author(s):  
Andrea Nesterović ◽  
Jelena Vukmirović ◽  
Ivan Stijepović ◽  
Marija Milanović ◽  
Branimir Bajac ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Pyrochlore Phase ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Low Dielectric ◽  
Long Time ◽  
Time Periods

The influence of different processing parameters and various Ba 2+ addition (up to 10 mol%) on the structure and dielectric properties of Bi 0.5 Na 0.5 TiO 3 -BaTiO 3 (BNT-BT) ceramics was investigated. The powders were hydrothermally synthesized in the alkaline environment at 180°C for different time periods. X-ray diffraction confirmed the presence of dominant rhombohedral Bi 0.5 Na 0.5 TiO 3 phase and a small amount of secondary pyrochlore Bi 2 Ti 2 O 7 phase in the pure BNT powders. In addition, one-dimensional Na 2 Ti 2 O 7 structure was also observed in the powder hydrothermally treated for a long time (i.e. 48 h). The amount of secondary pyrochlore phase in the BNT-BT powders increases with the increase of Ba 2+ content. The synthesized powders were pressed into pellets and finally sintered at various temperatures up to 1150°C. High density (more than 90%TD) was obtained in all BNT-BT sintered samples. Optimal sintering parameters were chosen in order to obtain dense ceramics with the optimal phase composition. The temperature dependence of dielectric properties for the BNT-BT ceramics was also studied. Relaxor behaviour of BNT-based ceramics and broad transition peaks are evident in all samples. Dielectric constant up to 400 as well as an acceptable low dielectric loss at temperatures lower than 200°C were obtained in BNT-BT ceramics.

scholarly journals Calcium titanate ceramics obtained by combustion synthesis and two-step sintering

2020 ◽  
Vol 52 (4) ◽  
pp. 491-502
Author(s):  
Kanchana Maitreekeaw ◽  
Tawat Chanadee
Keyword(s):  
Dielectric Constant ◽  
Combustion Synthesis ◽  
Xrd Analysis ◽  
Calcium Titanate ◽  
Single Step ◽  
Dielectric Constants ◽  
Sintered Ceramic ◽  
Relaxation Polarization ◽  
Titanate Ceramics ◽  
Titanate Ceramic

Calcium titanate powder was successfully prepared from duck eggshell and anatase titanium dioxide with a magnesium inductant via combustion synthesis in argon. As-combusted products were leached with diluted HCl. In XRD analysis, as-leached powders exhibited a major phase of CaTiO3 with a perovskite structure. The particle size, observed by SEM, was approximately 240 nm. As-leached powders were densified by single-step (SST) and two-step sintering (TSS) to produce calcium titanate ceramics. The first step of all TSS conditions was fixed at 1350C and holding times (t1) at this temperature were varied up to 120 min. Calcium titanate ceramic obtained from holding for 120 min had a grain size of 2.18 ?m, relative density of 86.68% and a dielectric constant of 92. Two-step sintered ceramic had the highest density (95.73%) and best dielectric properties (dielectric constant = 110, dielectric loss = 0.02) when the holding temperature (T2) was 1250?C. Calcium titanate ceramics processed by two-step sintering had denser microstructures and higher dielectric constants than single-step sintered ceramic due to grain boundary diffusion and the simplicity of relaxation polarization.

scholarly journals Ferroelectric Properties of Strontium Bismuth Titanate (SrBi4Ti4O15) Synthesized Using Solution Combustion Technique

Nano Hybrids ◽  
2013 ◽  
Vol 3 ◽  
pp. 67-79 ◽  
Author(s):  
Saransh Shrivastava ◽  
Oroosa Subohi ◽  
M.M. Malik
Keyword(s):  
Single Phase ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
X Ray ◽  
Low Dielectric ◽  
Combustion Technique ◽  
Single Phase Formation ◽  
Ferroelectric Transition Temperature

The ferroelectric properties of layer-structured Strontium Bismuth Titanate (SBT) have been investigated in this study. SBT was prepared using solution combustion technique with glycine as a fuel. Single-phase formation of the layer-structured compound of SBT with orthorhombic structure was achieved after calcinations at 800 °C, and was confirmed by x-ray diffraction studies. Scanning electron micrograph shows that the grains exhibit a plate like morphology and possesses ne particle size. The as prepared sample exhibits ferroelectric properties with remnant polarization of 2Pr = 1.84 μC/cm2at coercive field 2Ec= 2.61 kV/cm and displays low dielectric loss. Its ferroelectric transition temperature (Tc) is found to be 450 °C.

Dielectric and Piezoelectric Properties of Zirconium-Doped Bismuth Sodium Titanate Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 133-136 ◽  
Author(s):  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Dielectric Constant ◽  
Single Phase ◽  
Sodium Titanate ◽  
Bismuth Sodium Titanate ◽  
X Ray Diffraction ◽  
Unit Cell Size ◽  
Systematic Shift ◽  
Titanate Ceramics ◽  
Dielectric And Piezoelectric Properties ◽  
Bismuth Sodium

Zirconium-doped bismuth sodium titanate ceramics were prepared using the conventional processing method. X-ray diffraction analysis indicated the materials were single phase with a systematic shift due to increased unit cell size. The measured densities and grain size of the ceramic samples were found to range from 5.79-6.03 g/cm3 and 0.5-1.6 µm, respectively. The dielectric constant as a function of temperature became broader as Zr content increased. The piezoelectric constant was found to decrease with increasing Zr. Within the range of the solid solutions investigated, the materials seem to be promising for high temperature applications where stable dielectric constant is required.

Sol-Gel Derived Pb(Zn1/3Nb2/3)O3-PbTiO3 Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
G. Teowee ◽  
K. C. McCarthy ◽  
F. S. McCarthy ◽  
D. G. Davis ◽  
J. T. Dawley ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Firing Temperature ◽  
Remanent Polarization ◽  
Single Phase ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Dissipation Factor ◽  
Pt Films

ABSTRACTA series of sol-gel derived PB(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) films, with various PbTiO3 contents, have been prepared on platinized Si wafers. The (l-x)PZN - xPT films fired to 700C became single phase perovskite for x > 0.7. In the PZN-0.1PT films, the films still contain pyrochlore phase at a firing temperature of 850C; the perovskite phase appeared at a firing temperature of 800C. The dielectric constant increased with increasing PT content, with a peak in dielectric constant at x = 0.8. PZN-PT films with x = 0.8 exhibited dielectric constant, dissipation factor, remanent polarization and coercive field values of 600, 0.10, 6 and 45 kV/cm respectively.

scholarly journals Synthesis and characterization of Ce and La modified bismuth titanate

2009 ◽  
Vol 3 (1-2) ◽  
pp. 88-95 ◽  
Author(s):  
Nikolina Pavlovic ◽  
Dejan Kancko ◽  
Mészáros Szécsényi ◽  
Vladimir Srdic
Keyword(s):  
Bismuth Titanate ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Grain Morphology ◽  
The Other ◽  
Synthesis And Characterization ◽  
Second Phase ◽  
Titanate Ceramics ◽  
Different Content

Bismuth titanate based nanopowders with the different content of La or Ce were synthesized by the modified sol-gel method. After calcination at 600?C, in addition to Aurivillius layered structure, a small quantity of cubic pyrochlore phase was detected in the La modified powders, while this second phase was much more pronounced in the Ce substituted powders. In fact, as the powder with the highest amount of Ce (Bi3CeTi3O12) has the pure pyrochlore phase it seems that the presence of Ce stabilizes the formation of this phase. This different influence of cerium and lanthanum could be explained by the incorporation of their ions on the different sites in the titanate structure. Bismuth titanate based ceramics, sintered at 1050?C/2h, had densities above 93% of theoretical density and characteristic plate-like grain morphology. Small quantity of cubic pyrochlore phase was detected only in the Ce modified bismuth titanate ceramics. On the other hand, lanthanum addition caused formation of smaller grain size with pronounced plate-like morphology. .

Single Step Combustion Synthesis for the Preparation of Bismuth Titanate Ceramics for Potential Applications

2012 ◽  
Vol 620 ◽  
pp. 429-434 ◽  
Author(s):  
Umar Al-Amani Azlan ◽  
Srimala Sreekantan ◽  
Ahmad Fauzi Mohd Noor ◽  
Khairunisak Abdul Razak
Keyword(s):  
Combustion Synthesis ◽  
Goodness Of Fit ◽  
Bismuth Titanate ◽  
Exothermic Peak ◽  
Single Step ◽  
Degree Of Crystallinity ◽  
Strong Interactions ◽  
Potential Applications ◽  
Hydrolysis Temperature ◽  
Titanate Ceramics

Bismuth titanate was systematically prepared by a single step combustion synthesis. Based on TG-DTA, the corresponding phase was completely obtained below 300°C, resulting in highly exothermic peak at 236°C. The formation of a single crystalline structure of Bi-layered with different degree of crystallinity was strongly affected by hydrolysis temperature. Goodness-of-fit indicator,Sfor entire samples was in the range of 1.55 1.94, which is acceptable for Rietveld refinement analysis. All Raman peaks became more intense and sharp with higher hydrolysis temperature, suggesting that the strong interactions between Ti-O bonding in BIT structure. The presence of peaks at 838 and 628 cm-1in the IR spectrum can be ascribed to the stretching vibrations of Bi-O and Ti-O, respectively. Besides, the obtained powders are very fine with minimal grain growth, resulting in agglomerated powders.

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