Influences of Excess PbO on Optical Properties and Microstructures of La Modified 0.75Pb (Mg1/3Nb2/3)O3-0.25PbTiO3 Electro-Optic Transparent Ceramics

2013 ◽  
Vol 745-746 ◽  
pp. 555-559 ◽  
Author(s):  
Wen Long Ji ◽  
Xi Yun He ◽  
Wen Xiu Cheng ◽  
Ping Sun Qiu ◽  
Xin Sen Zheng
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Phase Structure ◽  
Perovskite Structure ◽  
Second Phase ◽  
Transparent Ceramics ◽  
Precursor Method ◽  
Electro Optic ◽  
Average Grain Size ◽  
Columbite Precursor

La-modified 0.75Pb (Mg1/3Nb2/3)O3-0.25PbTiO3(PLMNT) electro-optic (EO) transparent ceramics were synthesized through a columbite precursor method. Excess PbO (10, 15 and 20 mol %) was added to study the effect on the transparency, electro-optic effect, and microstructures of PLMNT transparent ceramics. The phase structure of different samples can be identified as single perovskite structure with no second phase detected. The average grain size increased as the concentration of excess PbO increased from 10 mol% to 20 mol%. On the contrary, the transparency decreased with the increase of the concentration of excess PbO. When the concentration of excess PbO was 10 mol%, the transmittance was about 62% at 632.8nm. The EO coefficient was calculated through measuring the birefringence as a function of electric field. The EO coefficient increased with the increase of the concentration of excess PbO and the maximum EO coefficient reached 40.6×10-16(m/V)2 when the excess PbO was 20 mol%.

Comparative Study on Microstructure of Pb(Mg1/3Nb2/3)O3-PbTiO3 Ceramics

2005 ◽  
Vol 475-479 ◽  
pp. 1201-1204
Author(s):  
Chun Hong Li ◽  
Qiang Li ◽  
Feng Bing Song
Keyword(s):  
Grain Size ◽  
Comparative Study ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Precursor Method ◽  
Average Grain Size ◽  
Columbite Precursor ◽  
Better Than

(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 ((1-x)PMN-xPT, PMN-PT) with composition near the morphotropic phase boundary (MPB) were prepared by the columbite precursor method and the rutile precursor method respectively. Attention has been focused on the influence of process on microstructure of PMN-PT ceramics. The results show that the average grain size of ceramics is insensitive to composition for both above processes. The refinement and homogeneity on grain size in the rutile precursor method is better than that in the columbite precursor method.

Fabrication and Upconversion Luminescence of Highly Transparent Er:YAG Ceramics

2012 ◽  
Vol 185 ◽  
pp. 55-59 ◽  
Author(s):  
Xian Peng Qin ◽  
Jian Zhang ◽  
Hao Yang ◽  
De Wei Luo ◽  
Jan Ma ◽  
...  
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Solid State ◽  
Grain Boundary ◽  
Upconversion Luminescence ◽  
Secondary Phase ◽  
Transparent Ceramics ◽  
Vacuum Sintering ◽  
Average Grain Size ◽  
Sintering Method

Highly transparent Er:YAG ceramics with different Er concentration were fabricated by a solid-state reaction and vacuum sintering method. The optical properties, the microstructure and the upconversion luminescence of the Er:YAG ceramics were investigated. For 3 mm thick samples, the in-line transmittances of the as-fabricated Er:YAG ceramics at the wavelength of 1100 nm and 400 nm were about 84% and 82%, respectively, which was very close to the theoretical transmittance of YAG ceramics. The micrograph of the Er:YAG transparent ceramics exhibited a pore-free structure and the average grain size was about 10 μm. The grain boundary of the ceramics was clean and no secondary phase was detected. When pumped by a 980 nm LD, the strong green and red upconversion luminescences in the Er:YAG ceramics were observed. The different upconversion mechanisms depending on Er concentration in the Er:YAG ceramics were also discussed.

Structure and Piezoelectric Properties of PZN-PNN-PT Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 223-226 ◽  
Author(s):  
Jin Song Pan ◽  
Xiao Wen Zhang ◽  
Ke Pi Chen ◽  
Chao Lei
Keyword(s):  
Phase Structure ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Ferroelectric Ceramics ◽  
Phase Boundaries ◽  
Precursor Method ◽  
Pure Perovskite Phase ◽  
The Relationship ◽  
Columbite Precursor ◽  
Better Than

(1-x)(0.64PNN-0.36PT)-x(0.91PZN-0.09PT) ferroelectric ceramics with different x were synthesized by the columbite precursor method. The phase structure and piezoelectric properties were investigated. XRD profiles implied that with the increasing of x, samples could no longer maintain the pure perovskite phase. All the compositions were found to lie within the region of the morphotropic phase boundaries (MPBs) with different contents of rhombohedral and tetragonal phases. The piezoelectric coefficients for compositions with x £ 0.30 were obviously better than those for the rest ones and the composition with x = 0.15 exhibited the largest value of d33 among all the samples. The relationship between the structure and the piezoelectric properties was discussed.

Effect of rate controlled sintering on microstructure and electrical properties of ZnO doped with bismuth and antimony oxides

1997 ◽  
Vol 12 (9) ◽  
pp. 2447-2454 ◽  
Author(s):  
Gaurav Agarwal ◽  
Robert F. Speyer
Keyword(s):  
Grain Size ◽  
Liquid Phase ◽  
Grain Growth ◽  
Elevated Temperatures ◽  
Antimony Oxide ◽  
Second Phase ◽  
Dopant Content ◽  
Average Grain Size ◽  
Rate Controlled ◽  
Grain Boundary Pinning

Various rate controlled sintering (RCS) schedules were used on isostatically pressed particulate compacts of ZnO with Bi2O3 and Sb2O3 additives. For low additive content, smaller average grain sizes with more rapid RCS schedules were attributable to thermal schedules which minimized the time at elevated temperatures where grain growth could occur. β–Bi2O3, Zn7Sb2O12, and Zn2Sb3Bi3O14 phases formed during/after sintering. Elevated heat-treatment temperatures favored the formation of Zn7Sb2O12 and additional β–Bi2O3, while Zn2Sb3Bi3O14 was dominant in sintered samples where the RCS schedule did not result in temperatures in excess of 1100 °C. Zn2Sb3Bi3O14 precipitated during sintering, functioning as grain boundary pinning sites which impeded ZnO grain growth. Bismuth and antimony oxide-based liquid facilitated sintering at lower temperatures, which in turn resulted in decreased average grain size. Rapid RCS schedules for samples with low dopant content resulted in lower sintering temperatures, since time was not allowed for Zn2Sb3Bi3O14 precipitation to deplete the liquid phase. For higher dopant contents, liquid phase was adequately plentiful, wherein longer RCS schedules resulted in lower sintering temperatures. Increasing concentration of second phase generally fostered decreased grain size and attenuated the effect of thermal schedule on the microstructure. Electrical resistance and breakdown voltage increased consistent with decreasing ZnO average grain size.

Preparation of γ-AlON Transparent Ceramics by Pressureless Sintering

2014 ◽  
Vol 602-603 ◽  
pp. 226-229 ◽  
Author(s):  
Feng Chen ◽  
Fang Zhang ◽  
Jun Wang ◽  
Run Tian ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Flexural Strength ◽  
Relative Density ◽  
Carbothermal Reduction ◽  
High Strength ◽  
Nitrogen Atmosphere ◽  
Pressureless Sintering ◽  
Transparent Ceramics ◽  
Average Grain Size

In this paper, AlON powders were prepared by carbothermal reduction and nitridation method. By adding a mixture of Y2O3, La2O3 and MgO as sintering agent, transparent AlON ceramics with high strength were fabricated by pressureless sintering at 1950°C for 8h under nitrogen atmosphere. The obtained ceramic had a relative density of 99.9% and average grain size of 150μm. The transmittance of the 2mm thick ceramics was 82.4% at 1100nm and flexural strength was 300 MPa.

MgAl2O4 Transparent Nano-Ceramics Prepared by Sintering under Ultrahigh Pressure

2007 ◽  
Vol 280-283 ◽  
pp. 549-552 ◽  
Author(s):  
Xiang Hui Chang ◽  
Tie Cheng Lu ◽  
Ying Zhang ◽  
Xiang Jie Luo ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Ultrahigh Pressure ◽  
Transparent Ceramics ◽  
Grain Sizes ◽  
Average Grain Size ◽  
Temperature And Pressure ◽  
Sintering Characteristics ◽  
Sintering Condition

The first experimental work to produce transparent MgAl2O4 nano-ceramics was reported in this paper. The sintering characteristics of transparent nano-ceramics were investigated at relatively low temperature (800 ~ 1100°C) under ultrahigh pressure (2 ~ 5 GPa) using hydrostatic equipment. The morphologies and phases of ceramics were observed by means of SEM and XRD, respectively. The grain sizes of the ceramics are shown to be less than one hundred nanometers, far smaller than the sizes of common transparent ceramics. Furthermore, the higher the sintering temperature and pressure are, the greater the extent of densification is. At the same temperature, the higher the pressure is, the smaller the average grain size is. Under the same pressure, the higher the temperature is, the larger the average grain size is. The optimal sintering condition for preparing transparent nano-ceramics was also determined.

Fabrication and Spectroscopic Properties of (Ho0.01La0.10Y0.89)2O3 Transparent Ceramics

2011 ◽  
Vol 299-300 ◽  
pp. 641-644 ◽  
Author(s):  
Dong Dong Huang ◽  
Qiu Hong Yang ◽  
Yong Gang Wang ◽  
Hao Jia Zhang
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Spectroscopic Properties ◽  
Gain Medium ◽  
Emission Peak ◽  
Transparent Ceramics ◽  
Laser Gain

Highly transparent (Ho0.01La0.10Y0.89)2O3 transparent ceramics were fabricated by the conventional ceramics processing with nanopowders. The microstructure, the optical properties and the spectroscopic properties of (Ho0.01La0.10Y0.89)2O3 ceramics were investigated. (Ho0.01La0.10Y0.89)2O3 ceramics with the grain size of ~50 μm were obtained by sintering at 1530 °C for 45 h. The highest in-line transmittance reaches 65%. The emission peak located at 2 μm wavelength indicates (Ho0.01La0.10Y0.89)2O3 transparent ceramics is suitable for 2 μm laser gain medium.

scholarly journals Improvement of optical properties and suppression of second phase exsolution by doping fluorides in Y_3Al_5O_12 transparent ceramics

2014 ◽  
Vol 4 (9) ◽  
pp. 1800
Author(s):  
Jintai Fan ◽  
Siyuan Chen ◽  
Benxue Jiang ◽  
Liangjie Pan ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Second Phase ◽  
Transparent Ceramics

Particle-Stimulated Nucleation of Recrystallization for Grain-Size Control in 01420 Al-Li Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 889-892 ◽  
Author(s):  
Ling Ying Ye ◽  
Xin Ming Zhang ◽  
Yu Xuan Du ◽  
Zhi Hui Luo
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Size Control ◽  
S Phase ◽  
Second Phase ◽  
Β Phase ◽  
Nucleation Sites ◽  
Second Phase Particles ◽  
Average Grain Size ◽  
Grain Size Control

Grain refinement of 01420 Al-Li alloy through particle stimulated nucleation(PSN) of recrystallization is reported. The results showed that the rolling in the overaged 01420 Al-Li alloy resulted in the formation of the deformation zones associated with the second phase particles larger than 0.80 μm which can act as the nucleation sites for recrystallized grains. The precipitates larger than 0.80 μm are sticked shaped S-phase(Al2MgLi) and globular β-phase(Mg2Al3), and the density of β-phase particles is approximately as two to three times as the S-phase particles. The S-phase particles can’t be as PSN sites since they were broken to small dispersoid particles during rolling. The average grain size of 01420 Al-Li alloy solutioned at 470°C for 2h, aged at 300 °C for 48h, 81% rolled at 300 °C and finally recrystallized at 500 °C for 10min is approximately 10 μm.

scholarly journals Формирование двухфазной структуры в металлоорганическом перовските CH-=SUB=-3-=/SUB=-NH-=SUB=-3-=/SUB=-PbI-=SUB=-3-=/SUB=-

2020 ◽  
Vol 54 (6) ◽  
pp. 543
Author(s):  
Д.В. Амасев ◽  
В.Г. Михалевич ◽  
А.Р. Тамеев ◽  
Ш.Р. Саитов ◽  
А.Г. Казанский
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Phase Structure ◽  
Perovskite Structure ◽  
Relative Content ◽  
Semiconductor Materials ◽  
Lead Iodide ◽  
Two Phase ◽  
Annealing Conditions ◽  
Planar Structures

The effect of annealing of organometallic perovskite CH3NH3PbI3 film on its electrical, photoelectric, and optical properties is studied. It was shown that annealing at Та>140 °C leads to the two-phase structure formation consisting of perovskite and lead iodide, the relative content of which depends on the annealing conditions, in particular, on its temperature. The PbI2 formation in the perovskite structure leads to a decrease in the conductivity and photoconductivity of the material. Our studies indicate the possibility of forming planar structures consisting of semiconductor materials with various values of the band gap: 1.6 eV (CH3NH3PbI3) and 2.4 eV (PbI2).

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