High Curie temperature perovskite BiInO3–PbTiO3 ceramics

2004 ◽  
Vol 19 (7) ◽  
pp. 2185-2193 ◽  
Author(s):  
Runrun Duan ◽  
Robert F. Speyer ◽  
Edward Alberta ◽  
Thomas R. Shrout
Keyword(s):  
Curie Temperature ◽  
Sol Gel ◽  
High Curie Temperature ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Compound Formation ◽  
X Ray ◽  
Oxide Powders ◽  
Phase Pure ◽  
Pbtio3 Ceramics

The extent of BiInO3 substitution in the perovskite system xBiInO3–(1 - x)PbTiO3 and the corresponding raise in the Curie temperature were investigated using thermal analysis, dielectric measurements, x-ray diffraction, and electron microscopy. Maximum tetragonal perovskite distortion (c/a = 1.082) was obtained for x = 0.20, with a corresponding Curie temperature of 582 °C. Phase-pure tetragonal perovskite was obtained for x ⩽ 0.25. Compound formation after calcining mixed oxide powders resulted in agglomerated cube-shaped tetragonal perovskite particles, which could be fired to 94.7% of theoretical density (TD). Sol-gel fabrication resulted in nano-sized tetragonal or pseudo-cubic perovskite particles, which after two-step firing, resulted in a tetragonal perovskite microstructure at as high as (x = 0.20) 98.1% of TD.

Nanostructured TiO2-Based Composites for Light Absorption

2014 ◽  
Vol 975 ◽  
pp. 207-212
Author(s):  
Dayse I. dos Santos ◽  
Olayr Modesto Jr. ◽  
Luis Vicente A. Scalvi ◽  
Americo S. Tabata
Keyword(s):  
Metal Oxide ◽  
Light Absorption ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Oxide Powders

Metal oxide nanocomposites were prepared by two different routes: polyol and sol-gel. Characterization by X ray diffraction showed that the first process produces directly a two-phase material, while the sol-gel powder never showed second phase below 600°C. Light spectroscopy of the treated powders indicated similarities for the processed materials. Although the overall material compositions are about the same, different structural characteristics are found for each processing. With the exception of Ti-Zn materials, all the double metal oxide powders showed higher absorbance than either TiO2 powder.

scholarly journals Effect of Polymers (PEG and PVP) on Sol-Gel Synthesis of Microsized Zinc Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Thilagavathi Thirugnanam
Keyword(s):  
Sol Gel ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Modifications ◽  
Phase Pure ◽  
Sol Gel Synthesis ◽  
Polyethylene Glycol 6000 ◽  
Granular Morphology ◽  
Scanning Electron

Fibers irregular and seed-like microcrystalline ZnO were synthesized by using a cost-effective and low temperature aqueous sol-gel method. Various polymers, namely, polyethylene glycol 6000 (PEG 6000) and polyvinyl pyrrolidone (PVP), were used as structure directing agents. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The X-ray diffraction pattern revealed the formation of phase-pure ZnO micropowders. It is observed that the polymers play an important role in modifying the surface morphology and the size of the crystallites. A compact granular morphology is observed for the ZnO samples without polymer. The samples exhibit microparticles of size 100 nm for PVP and for PEG-mediated growth, whereas microporous corrugated morphology is observed for added PEG-mediated micropowder. FTIR study is used to confirm the structural modifications occurring in the polymers.

Effects of Glass Elements on the Structural Evolution ofin situGrown Ferroelectric Perovskite Crystals in Sol-gel Derived Glass-ceramics

1997 ◽  
Vol 12 (4) ◽  
pp. 1131-1140 ◽  
Author(s):  
Kui Yao ◽  
Weiguang Zhu ◽  
Liangying Zhang ◽  
Xi Yao
Keyword(s):  
Crystallization Process ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Structural Evolution ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Process Change ◽  
X Ray ◽  
Ferroelectric Perovskite

Several ABO3perovskite ferroelectric crystals, PbTiO3, Pb(Zr, Ti)O3, and BaTiO3have beenin situgrown from amorphous gels with glass elements, and the structural evolution has been systematically investigated using x-ray diffraction (XRD), infrared spectra (IR), differential thermal analysis (DTA), thermogravimetric analysis (TGA), and dielectric measurements. It is found that in the Si-contained glass-ceramic systems, Si and B glass elements are incorporated into the crystalline structures, resulting in the variation of the crystallization process, change of lattice constant, and dielectric properties. Some metastable phases expressed by a general formula AxByGzOw(A = Pb and Ba; B = Zr and Ti; G for glass elements, especially for Si) have been observed and discussed.

scholarly journals Phase diagram and dielectric properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics

2015 ◽  
Vol 05 (02) ◽  
pp. 1550014 ◽  
Author(s):  
Dabin Lin ◽  
Haohua Chen ◽  
Zhenrong Li ◽  
Zhuo Xu
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
X Ray ◽  
Pbtio3 Ceramics ◽  
Curie Temperatures ◽  
Columbite Precursor ◽  
Tetragonal Phase Transition

x Pb ( In 1/2 Nb 1/2) O 3- Pb ( Mg 1/3 Nb 2/3) O 3- PbTiO 3(x PIN –y PMN –z PT ) ternary ceramics with morphotropic phase boundary (MPB) composition were synthesized by columbite precursor method. x PIN –y PMN –z PT phase diagram was investigated by x-ray diffraction and dielectric measurements. According to the results of dielectric measurements, the Curie temperatures (Tc) and rhombohedral to tetragonal phase transition temperature (Tr−t) were found to be in the range of 173–212°C and 114–155°C, respectively, indicating that the Tr-t was increased with adding PIN component. In the MPB region, the highest Tr-t = 155° C was found in 0.32PIN–0.38PMN–0.30PT ceramic, that greatly expanded temperature usage range.

The Effect of Substituting of Al on the Curie Temprature and Magneto-Resistance of Double Perovskite Compounds

2012 ◽  
Vol 548 ◽  
pp. 341-344
Author(s):  
Xiang Hu Li ◽  
Dan Li
Keyword(s):  
Curie Temperature ◽  
Sol Gel ◽  
Double Perovskite ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Al Substitution ◽  
Diffraction Patterns ◽  
Magneto Resistance ◽  
Fe Substitution

The compounds of Fe substitution of Al in nanotructured Sr2Fe1-xAlxMoO6(0≤x≤0.2) double perovskite have been prepared by sol-gel method. The x-ray diffraction patterns of the samples show that the samples are in nanometer range. The Curie temperature and thesaturation magnetization of the samples decrease with the increasing of Al substitution. And the magnetoresistance of the samples increase with the increasing of x.

X-Ray Diffraction and Raman Scattering Study of Sr1-xBi2+yTa2O9 Nanoparticles

2005 ◽  
Vol 475-479 ◽  
pp. 3539-3542
Author(s):  
Yu Zhou ◽  
Hua Ke ◽  
De Chang Jia ◽  
W. Wang ◽  
J.C. Rao
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Curie Temperature ◽  
Size Effects ◽  
Sol Gel ◽  
Large Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Study ◽  
The Stability

Sr1-xBi2+yTa2O9 (x, y=0.2, 0) nanoparticles, synthesized by a sol-gel method, are investigated by X-ray diffraction and Raman spectroscopy. Large structure distortion shows the size effects in nanoparticles, which gives rise to the Raman bands broadening. The Bi content is the most important factor responsible for non-stoichiometric SrBi2Ta2O9 structure distortion and providing the larger ferroelectric spontaneous polarization and the higher Curie temperature. The stability of the crystal structure is discussed in consideration of inner compressive stress in nanoparticles.

Piezoelectric and Dielectric Properties of MnO2-Modified Bi(Mg1/2Ti1/2)O3–PbTiO3

2011 ◽  
Vol 415-417 ◽  
pp. 1983-1987
Author(s):  
Xiao Na Wang ◽  
Qing Chi Sun ◽  
Wei Bing Ma ◽  
Tao Liu ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Curie Temperature ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
High Curie Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stable Temperature ◽  
Curie Temperature Tc ◽  
Dielectric And Piezoelectric Properties

We reported that Bi(Mg1/2Ti1/2)O3–PbTiO3(BMT-PT) systems had high piezoelectric, dielectric performances and high Curie temperature. The phase structure of the system was identified by X-ray diffraction analysis. The piezoelectric and dielectric properties were also investigated. The results showed that 0.6BMT–0.4PT (Mg/Ti = 0.5:0.5) with 1mol% MnO2was the optimum composition which exhibited the highest curie temperature Tc = 511 °C and the stable temperature of dielectric loss reached to 500 °C. Further, the dielectric and piezoelectric properties of this composition were given as follows:kp = 22.5%;εr= 734; room temperature d33= 131.3 pC/N; tanδ = 1.96%.

scholarly journals Modified Structural and Magnetic Properties of Ni-Mn-Zn Ferrite Nanoparticles Doped with Ce3+Ions

2021 ◽  
Vol 12 (4) ◽  
pp. 5021-5030
Keyword(s):  
Spinel Ferrite ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Sem Analysis ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
High Frequency Region ◽  
X Ray ◽  
Zn Ferrite ◽  
Xrd Patterns

Polycrystalline Ni-Mn-Zn nano-ferrites doped by the fractional amount of Ce3+ ions were fabricated using the sol-gel method. Characterizations of the as-prepared samples were performed by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), vibrating sample magnetometer (VSM), and dielectric measurements. Rietveld refined XRD patterns revealed the single-phase cubic spinel structure of the samples corresponds to the space group Fd-3m. Minor shifting of peak positions towards lower diffraction angles increases lattice parameter from 8.4105 to 8.4193 Å with the addition of Ce3+ ions. , The surface morphology and homogeneity of the samples were investigated by using SEM and EDAX spectra. Grain size obtained from SEM analysis is found in the range 29 nm to 33 nm with negligible agglomeration. Analysis of EDAX spectra confirms the stoichiometric proportion of the constituents. Substitution of Ce3+ ions shows typical ferromagnetic curves with enhanced saturation magnetization and magneton number from 54 to 63 emu/gm and 2.71 to 3.09 B respectively. Dielectric measurements of the entire samples show the typical behavior of spinel ferrite. The results predict that the samples are best suitable for high-frequency region applications.

Effect of Sintering Temperature on Phase Formation and Dielectric Properties of PLZT-BT Ceramics

2015 ◽  
Vol 1120-1121 ◽  
pp. 7-10
Author(s):  
Ladapak Chumprasert ◽  
Narit Funsueb ◽  
Apichart Limpichaipanit ◽  
Athipong Ngamjarurojana
Keyword(s):  
Dielectric Properties ◽  
Lead Zirconate Titanate ◽  
Sintering Temperature ◽  
Lead Zirconate ◽  
Rhombohedral Structure ◽  
Relaxor Behavior ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Powders

In this research, Barium titanate (BT) additive in lanthanum modified lead zirconate titanate (PLZT) was used to stabilize the PLZT ceramics. Oxide powders were synthesized by mixed oxide synthetic route via a rapid vibro-milling technique. It was prepared with the chemical formula of 0.95 Pb0.91La0.09 (Zr0.65Ti0.35)0.9775O3 -0.05 BaTiO3 to investigate the dielectric properties of PLZT ceramics. The modified PLZT ceramics were fabricated at variation of sintering temperatures of 1200-1275°C for 4 hours. By employing X-ray diffraction (XRD), it was found a pure perovskite with rhombohedral structure. The relaxor behavior was observed from the dielectric measurements. The suitable sintering temperature of 0.95 PLZT - 0.05 BT was 1275°C (εr=10463, tanδ=0.0125 and Tm=70°C).

Synthesis and Characterization of Bi2Al4O9 Powders

2012 ◽  
Vol 624 ◽  
pp. 34-37
Author(s):  
Xiao Yan Zhang ◽  
Wen Shu Hu ◽  
Xi Wei Qi ◽  
Gui Fang Sun ◽  
Jian Quan Qi ◽  
...  
Keyword(s):  
Crystallization Process ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Oxide Powders ◽  
Sol Gel Process ◽  
Ft Ir

Bi2Al4O9 powders were prepared by sol-gel process. The precursors were heated at 500-800°C for 2h to obtain Bi2Al4O9 powder and X-ray diffraction (XRD), Differential thermal analysis (DTA), thermogravimetric analysis (TG), field emission scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) techniques were used to characterize precursor and derived oxide powders. XRD analysis show that the powder is still amorphous after calcined at 500°C. The peaks of Bi2Al4O9 become sharp after calcined at 575°C though still existing some amorphous phase. After calcining at 675-800°C, the powder has fully turned into pure Bi2Al4O9 phase. The crystallization process can also be confirmed by DTA-TG and IR. Calcining the precursor at 575°C, the absorption bands at 527 cm-1, 738 cm-1, 777 cm-1, and 919 cm-1are observed, which are assigned to Bi2Al4O9 and becoming stronger and sharper with the increase of temperature.

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