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.

The present paper reports the dependence of dielectric, ferroelectric and piezoelectric properties on the porosity level in BaZr_0.15Ti_0.85O₃ ceramics with porosity from 5% to 21%. Microporosity with 0–3 connectivity has been produced using PMMA microspheres as a sacrificial template. The functional properties (dielectric, ferroelectric and piezoelectric effect) are mostly affected by the “dilution effect”: permittivity decreases by 40% when porosity increases by 21%, and P_max decreases from 13 to 5 µC/cm² while the P_rem is in the range of (2–8) µC/cm². However, the reduction of the zero-field permittivity and hysteretic behaviour of ε(E) while the tunability level is still high makes from porous ceramics interesting materials for tunability application.

The aim of this study is to investigate the influence on the magnetorheological (MR) fluids of two aspects which characterize magnetic powders: particles size and particles sizer distribution. We obtained Fe powders with micrometric particles of different sizes and narrow size distribution by sieving commercially available Fe powder by means of a sieve shaker. Also, three powders with particles having normal size distributions with the same mean size and different variances have been tailored using the sieved Fe powders. MR fluids based on the resulted magnetic powders were prepared and studied by means of a rheometer with a magnetorheological module. A correlation between the MR performance and particles size/particles size distribution was observed.