SYNTHESIS OF CuNi NANOPARTICLES WITH SOL GEL METHOD

Magnetni nanodelci baker-nikelj (CuNi) zlitine z različnimi sestavami so bili pripravljeni v procesu, ki vključuje štiri korake: priprava začetnega prekurzorja v SiO2 matrici s sol gel metodo in naknadno dekompozicijo, toplotno obdelavo in redukcijo. Redukcija ima dva namena, prvi je redukcija mešanih CuNi oksidov do CuNi zlitine, drugi pa je homogenizacija nanodelcev CuNi zlitine v redukcijski atmosferi. Rentgensko praškovno difrakcijo smo uporabili za kvalitativno analizo in oceno velikosti CuNi nanodelcev. S transmisijsko elektronsko mikroskopijo (TEM) smo pregledali morfologijo sintetiziranih vzorcev. Z modificirano termogravimetrično analizo (TGA) smo določili Curiejevo temperaturo (Tc) pripravljenih CuNi nanodelcev. Rezultati z modificirano TGA analizo kažejo, da Curiejeva temperatura raste z vsebnostjo Ni v vzorcu po termični obdelavi v cevni peči pri 850°C v redukcijski Ar/H2 atmosferi, kar potrjuje naša pričakovanja. Cilj diplomskega dela je bil sintetizirati magnetne nanodelce CuNi v SiO2 matrici, ki imajo primerne magnetne lastnosti in Curiejevo temperaturo okoli 42°C, ki je optimalna temperatura za propad rakavih celic. Taki magnetni nanodelci so samoregulativni in se lahko uporabljajo v magnetni hipertermiji.Magnetic nanoparticles of copper-nickel (CuNi) alloys with different stoichiometry were prepared in a process which involves four steps: preparation of starting precursor in SiO2 matrix by sol-gel method and subsequent decomposition, annealing and reduction. The reduction step has two purposes: first is reduction of the CuNi mixed oxides to a CuNi alloy and second is the homogenization of a CuNi alloy nanoparticles in a reductive atmosphere. We used X-ray powder diffraction (XRD) for qualitative analysis and estimation of the crystallite size of CuNi nanoparticles. Transmission electronic microscope (TEM) was used to inspect the morphology of synthesized samples. By modified thermogravimetric analysis (TGA) we determined Curie temperature (Tc) of prepared CuNi nanoparticles. Results from modified TGA - measurements show that Curie temperature increases with Ni content in the sample after thermal treating in a tube furnace at 850°C in reducing Ar/H2 atmosphere, which confirms our expectations. The aim of this diploma work was to synthesize the magnetic nanoparticles of CuNi in SiO2 matrix, which have appropriate magnetic properties and Curie temperature near 42°C, which is an optimal temperature to cause necrosis of cancer cells. Such magnetic nanoparticles are self-regulative and can be used in application of magnetic hyperthermia