Magnetic nanocomposite thin films of NiFe2O4/SiO2 prepared by sol–gel process

2003 ◽  
Vol 214 (1-4) ◽  
pp. 143-150 ◽  
Author(s):  
Nelcy D.S. Mohallem ◽  
Luciana M. Seara
2019 ◽  
Vol 4 (1) ◽  
pp. 467-472 ◽  
Author(s):  
Luciana M. Seara ◽  
José D. Ardisson ◽  
Nelcy D. Mohallem

2006 ◽  
Vol 36 (3b) ◽  
pp. 1078-1080 ◽  
Author(s):  
Nelcy D. S. Mohallem ◽  
Luciana M. Seara ◽  
Miguel A. Novak ◽  
Elis H. C. P. Sinnecker

Author(s):  
Nelcy Della Santina Mohallem ◽  
Marcelo Machado Viana ◽  
Magnum Augusto Moraes Lopes de Jesus ◽  
Gustavo Henrique de Magalhães Gomes ◽  
Luiz Fernando de Sousa Lima ◽  
...  

2003 ◽  
Vol 775 ◽  
Author(s):  
Nelcy D. S. Mohallem ◽  
Luciana M. Seara

AbstractMagnetic nanocomposite thin films formed by cobalt ferrite dispersed in silica matrix were prepared by sol-gel process using tetraethylorthosilicate (TEOS) as a precursor of silica, and metallic nitrates as precursors of the ferrite. The films were prepared with 5–50 wt. % ferrite contents and deposited on substrate using the dip-coating process. The films obtained were adherent, transparent, homogeneous and free of microcracks, with thickness between 30 and 500 nm. The films obtained presented crystalline CoFe2O4 phases dispersed in SiO2 amorphous matrix and saturation magnetization of approximately 9 emu/g considering the composite mass and 30 emu/g considering the ferrite mass.


Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.


1999 ◽  
Vol 606 ◽  
Author(s):  
Keishi Nishio ◽  
Jirawat Thongrueng ◽  
Yuichi Watanabe ◽  
Toshio Tsuchiya

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).


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