Making lightweight SiC(rGO, xMoSi 2 ) bulk ceramics via polymeric precursor route

We have demonstrated here the study of memory effect, relaxation and interaction of hydrothermally grown La0.7Sr0.3MnO3 (LSMO-0.3) nanowires (NWs) and its bulk form synthesized by using polymeric precursor route. Magnetic relaxation measurement has been performed and the analysis shows the existence of two relaxation times in both the cases. It has been observed that both the samples show signature of magnetic memory effect and prefer magnetized state. Curie temperature of La0.7Sr0.3MnO3 (LSMO-0.3) NWs is decreased compared to its bulk form due to finite size effects.

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Magnetotransport in La0.7Ca0.3MnO3–PMMA composites synthesized by polymeric precursor route

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2007.01.028 ◽

2008 ◽

Vol 455 (1-2) ◽

pp. 289-294 ◽

Cited By ~ 17

Author(s):

Jitendra Kumar ◽

Rajiv K. Singh ◽

H.K. Singh ◽

P.K. Siwach ◽

Ramadhar Singh ◽

...

Keyword(s):

Polymeric Precursor ◽

Precursor Route

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Wet Chemical Synthesis of La1-xSrxGa0.8Mg0.2O3-δ (x=0.1, 0.2, 0.3) Powders

Materials Science Forum ◽

10.4028/www.scientific.net/msf.636-637.908 ◽

2010 ◽

Vol 636-637 ◽

pp. 908-913 ◽

Cited By ~ 1

Author(s):

D. Kioupis ◽

Anna Gaki ◽

Glykeria Kakali

Keyword(s):

Citric Acid ◽

Ethylene Glycol ◽

Chemical Synthesis ◽

Single Phase ◽

Complexing Agents ◽

Polymeric Precursor ◽

Wet Chemical Synthesis ◽

Wet Chemical ◽

Precursor Route

In the present work a modified polymeric precursor route is applied for the preparation of La1-xSrxGa0.8Mg0.2O3-δ (x=0.1, 0.2, 0.3). Citric acid and ethylene glycol are used as chelating and complexing agents respectively and microwave heating is used for the preparation of the precursors. The sintering reactions are recorded using TG/DTG measurements, while XRD, FTIR and SEM are used for the characterization of the intermediate and final products. As it is concluded, pure La0.9Sr0.1Ga0.8Mg0.2O3 can be prepared after sintering at 1300 °C for 6h. As the doping level of Sr increases, the formation of single phase perovskite is hindered. La0.8Sr0.2Ga0.8Mg0.2O3 contains minor amounts of SrLaGa3O7, while single-phase La0.7Sr0.3Ga0.8Mg0.2O3 can not be prepared at all. In all cases, the intermediate products at lower temperatures are mainly SrLaGa3O7, SrLaGaO4, La4Ga2O7 and La carbonates.

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Synthesis, Characterization and Electrical Properties of Single Phase La0.9Sr0.1Ga0.8Mg0.2O3

Materials Science Forum ◽

10.4028/www.scientific.net/msf.636-637.874 ◽

2010 ◽

Vol 636-637 ◽

pp. 874-879

Author(s):

Anna Gaki ◽

G. Kakali ◽

R.J. Wiglusz ◽

W. Strek ◽

Grzegorz Paściak

Keyword(s):

Grain Size ◽

Electrical Properties ◽

Impedance Spectroscopy ◽

Single Phase ◽

Sintered Sample ◽

Polymeric Precursor ◽

Secondary Phases ◽

Sem Images ◽

Xrd Pattern ◽

Precursor Route

Single phase La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM9182) was synthesized by a polymeric precursor route. The XRD pattern after calcination at 1300 °C for 6h indicates the formation of the perovskite without the presence of secondary phases. XRD, FTIR and TG-DTG measurements were used to examine the powder precursor as well as the intermediate and final products. SEM images indicated the small grain size of the final product. The conductivity of the sintered sample was examined by means of a.c. impedance spectroscopy and was found to be 9.10-2 S/cm at 800 °C similar to the typical value of LSGM materials.

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Lanthanum ferrite ferromagnetic nanocrystallites by a polymeric precursor route

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2010.12.162 ◽

2011 ◽

Vol 509 (10) ◽

pp. 4108-4116 ◽

Cited By ~ 40

Author(s):

Monica Popa ◽

Jose M. Calderon Moreno

Keyword(s):

Polymeric Precursor ◽

Lanthanum Ferrite ◽

Precursor Route

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Synthesis of Nanosized Zirconium Carbide (ZrC) by a Polymeric Precursor Route

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.373 ◽

2011 ◽

Vol 393-395 ◽

pp. 373-376

Author(s):

Xue Yu Tao ◽

Wen Feng Qiu ◽

Hao Li

Keyword(s):

Dynamic Change ◽

Zirconium Carbide ◽

Ceramic Matrix Composites ◽

Matrix Composites ◽

Polymeric Precursor ◽

X Ray ◽

Preceramic Polymers ◽

Heat Treated ◽

Precursor Route ◽

Size And Morphology

Based on the basic principle of carbothermal reduction reactions in the ZrO2-C system, nanosized ZrC powders were synthesized by the preceramic method using Polyzirconoxane (PZO) and salicyl alcohol (SA) as sources of zirconia and carbon respectively. The obtained polymeric precursor exhibited excellent solubility and rheology for the processing of ceramic matrix composites. Thermal dynamic change process, phase composition, crystallite size and morphology of the synthesized powders were characterized by Thermogravimetric analysis (TGA)、 Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). When heat-treated at 900 °C under flowing argon, precursors transformed into intimately mixed amorphous carbon and nanosized tetragonal ZrO2. Further heat treatments (1300 °C) led to the formation of zirconium carbide with a yield of 70.6 %. The obtained ZrC particles exhibit cubic morphology with size ranged in 50-100 nm. This study displays the preparation of nanosized ZrC materials from the preceramic polymers.

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Synthesis of calcium aluminates through the polymeric precursor route

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq0602137g ◽

2006 ◽

Vol 12 (2) ◽

pp. 137-140 ◽

Cited By ~ 4

Author(s):

A. Gaki ◽

R. Chrysafi ◽

Th. Perraki ◽

G. Kakali

Keyword(s):

Solid State ◽

High Purity ◽

Pechini Method ◽

Solid State Synthesis ◽

Polymeric Precursor ◽

Secondary Phases ◽

Calcium Aluminates ◽

Polycrystalline Ceramics ◽

Precursor Route

The Pechini method is a polymeric precursor route for the synthesis of polycrystalline ceramics of high purity. The conventional solid state synthesis of calcium aluminate compounds requires long-term lasting sintering at high temperatures. In this study, the Pechini method was applied for the preparation of pure CaO.Al2O3 and 3CaO.Al2O3. Solid state synthesis was also used in order to compare the final products obtained by the two methods. The intermediate and final products obtained were characterized by XRD and FTIR spectroscopy. It was concluded that the Pechini method can be successfully applied for the preparation of high purity CaO.Al2O3 and 3CaO.Al2O3. The formation of 3CaO.Al2O3 and CaO.Al2O3 requires three-hour sintering at 1000?C and 900?C, respectively. The main intermediate product was 5CaO.3Al2O3 in the case of 3CaO.Al2O3, while in the case of CaO.Al2O3 there were no other crystalline intermediate products. The samples prepared through solid state synthesis, contain a considerable amount of secondary phases, even after sintering at 1350-1400?C for more than 15 hours.

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