SYNTHESIS AND CHARACTERIZATION OF CuNi MAGNETIC NANOPARTICLES BY THE POLYOL METHOD

Namen diplomskega dela, je bil sintetizirati magnetne nanodelce Cu0,3Ni0,7 s poliolno metodo in pri tem ugotoviti vpliv različnih parametrov na potek reakcije ter velikost in obliko delcev. Kot poliol smo uporabili etilenglikol (EG) in dietilenglikol (DEG). Naredili smo različne sinteze, pri katerih smo spreminjali čas refluksa, množino soli, količino NaOH in količino PVP. S pomočjo difraktogramov, katere smo dobili kot rezultat rentgenske praškovne difrakcije, (RPD) smo ocenili velikost nanodelcev CuNi in določili faze v vzorcih. S termogravimetrično analizo (TGA) smo določili Curiejevo temperaturo vzorca. Na koncu smo preučili še morfologijo nanodelcev s pomočjo transmisijskega elektronskega mikroskopa (TEM). Iz rezultatov je mogoče razbrati vplive posameznih parametrov na velikost in obliko delcev. Izmerili smo optimalno Curiejevo temperaturo 43ºC, pri sintetiziranem vzorcu s poliolno metodo, z uporabo poliola EG. Vzorec je bil predhodno segret v cevni peči na 700 ºC, v Ar/H2 atmosferi.The aim of this work was to synthesize magnetic nanoparticles with composition Cu0,3Ni0,7 by the polyol method and to determine the effect of various parameters on the course of the reaction and the size and shape of the particles. We used ethylene glycol (EG) and diethylene glycol (DEG) as polyol. We preformed various syntheses in which the time of reflux, the both amounts of salts, the amounts of NaOH and the amounts of PVP was varied. The size of magnetic nanoparticles was estimated by Scherrer equation. Samples were characterized with XRD analysis. Curie temperature of the sample was studied using a modified TGA – SDTA method. The morphology of nanoparticles was studied with transmission electron microscopy (TEM). The results showed the effects of individual parameters on the size and shape of the particles. We measured the Curie temperature of 43ºC at sample with composition: Cu0,3Ni0,7, which was synthesized by standard polyol procedure (with ethylene glycol). The sample was tempered at 700 ºC in tube furnace in Ar/H2 atmosphere