The magnetic characteristics of FINEMET type glass-coated nanowires and submicron wires are investigated by taking into account the structural evolution induced by specific annealing all the way from a fully amorphous state to a nanocrystalline structure. The differences between the magnetic properties of these ultrathin wires and those of the thicker glass-coated microwires and “conventional” wires with similar structures have been emphasized and explained phenomenologically. The domain wall propagation in these novel nanowires and submicron wires, featuring a combination between an amorphous and a crystalline structure, has also been studied, given the recent interest in the preparation and investigation of new materials suitable for the development of domain wall logic applications.

Results on the preparation and magnetic characterization of rapidly solidified amorphous glass-coated nanowires are reported. Rapidly solidified nanowires have been investigated by means of bulk and surface hysteresis loop measurements, scanning electron microscopy, and ferromagnetic resonance. Domain wall velocity has been measured to demonstrate the suitability of the new nanowires for spintronic applications. Changes in composition, in the thickness of the glass coating, and nanowire dimensions allow extensive tailoring of the domain wall mobility.

Results on the magnetic behavior of glass-coated amorphous wires with metallic nucleus diameters in the submicron range are reported for the first time. The magnetic behavior of nearly zero magnetostrictive submicron amorphous wires is different from that observed in amorphous microwires with typical dimensions and similar composition. Submicron wires are bistable, whereas typical microwires show an almost anhysteretic loop. Bistability of submicron wires is maintained even in a very thin surface layer, which was shown to display a helical magnetic anisotropy. The origin of this specific behavior is the shape anisotropy which becomes dominant at lower dimensions of the metallic nucleus. The study of submicron amorphous wires opens up the way for new applications of amorphous wires.

The initial characteristics of Romanian fly ash from the CET II Holboca power plant show the feasibility of its application for the production of a new material with applicability in environmental decontamination. The material obtained was characterized using standard techniques: scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), instrumental neutron activation analysis (INAA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), the Brunauer–Emmett–Teller (BET) surface area, and thermogravimetric differential thermal analysis (TG-DTA). The adsorption capacity of the obtained material was evaluated in batch systems with different values of the initial Cu(II) ion concentration, pH, adsorbent dose, and contact time in order to optimize the adsorption process. According to the experimental data presented in this study, the adsorbent synthesized has a high adsorption capacity for copper ions (q_max = 27.32–58.48 mg/g). The alkali treatment of fly ash with NaOH improved the adsorption capacity of the obtained material compared to that of the untreated fly ash. Based on the kinetics results, the adsorption of copper ions onto synthesized material indicated the chemisorption mechanism. Notably, fly ash can be considered an important beginning in obtaining new materials with applicability to wastewater treatment.