Repository logo

Browsing by Author "Rajnak, Michal"

Now showing 1 - 2 of 2
  • Magnetic hysteresis loops revisited: step closer to understand the role of exterior angles
    Publication . Nikolić, Violeta N.; Rajnak, Michal; Morais Lopes, Fernando; Lazarov, Nenad Dj.
    The characterization of nanocomposite samples which contain Cu, Fe-species, prepared by the sol-gel method, was established by Nikolic et al., in a previous article (Nikolic et al. in Journal of Solid State Physics 513:1, 2021). In this study, the magnetic behavior of nanocomposite samples was examined The basic parameters of the room- and low-temperature magnetic hysteresis loops are discussed. To better describe the shape of magnetic hysteresis loop, the authors proposed to consider additional parameters - measures of the exterior angles of the hysteresis curve. Behavior of hysteresis parameters and exterior angles, caused by annealing treatment, was investigated by measuring hysteresis loops at two measured temperatures: 298K, and 5K. Correlation between changes in the behavior of hysteresis parameters and exterior angles was discussed. An attempt has been made to attribute physical meaning to chosen measured angles, which would allow a better understanding of the magnetic hysteresis curve.
    2022-03Journal article Restricted access Show more
  • Structural and magnetic properties of P25 TiO2 nanoparticles doped by Co
    Publication . Morais Lopes, Fernando; Bessergenev, Valentin; J. Lourenço, João Paulo Lourenço; Hantusch, Martin; Burkel, Eberhard; Botelho do Rego, Ana M.; Rajnak, Michal; Timko, Milan; Kopcansky, Peter
    The present work reports on the structural and magnetic properties of TiO2 P25 Degussa powder doped with cobalt. Dissolution of cobalt in TiO2 matrix was achieved by precipitation of tris(diethyldithiocarbamato) cobalt (III) (CoDtc - Co[S2CN(C2H5)(2)](3) in chloroform (CHCl3) and consequent thermal treatment. Five different Co atomic percentage contents were chosen, e.g., 0.5%, 1%, 2%, 5% and 10%. It was shown that cobalt atoms are uniformly distributed across TiO2 matrix and exhibit antiferromagnetic interactions at low temperatures.
    2020-05Journal article Restricted access Show more