امروز شنبه , 10 شهریور 1403
شنبه تا پنج شنبه - 9 صبح الی 20 عصر
دانلود مقاله : Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method 2013
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دانلود مقاله :
Thermal stability of silica-coated magnetite nanoparticles prepared by an electrochemical method 2013
نویسندگان :
Fauziatul Fajaroh , Heru Setyawan , Adrian Nur . Wuled Lenggoro
فرمت:pdf
چکیده :
Magnetite nanoparticles have been prepared by electrooxidation of iron in water. Surface modifications
have been conducted by coating the nanoparticles with silica by a one-step synthesis in dilute sodium
silicate solution. The mean size of particles was approximately 10–30 nm for the uncoated particles
and 9–12 nm for the coated particles. The results obtained from thermal gravimetric/differential thermal
analysis (TG/DTA) revealed that the silica layer formed by the electrochemical method was stable and
could serve as a protective layer. Annealing the nanoparticles at 550 C for 30 min converts magnetite
into maghemite for the silica-coated particles, and it further converts the uncoated particles into hematite.
The conversions cause the saturation magnetization to decrease for all samples.