Infection with pathogenic microorganisms is of great concern in many areas, especially in healthcare, but also in food packaging and storage, or in water purification systems. Antimicrobial polymer nanocomposites have gained great popularity in these areas. Therefore, this study focused on new approaches to develop thin antimicrobial films based on biodegradable polycaprolactone (PCL) with clay mineral natural vermiculite as a carrier for antimicrobial compounds, where the active organic antimicrobial component is antifungal ciclopirox olamine (CPX). For possible synergistic effects, a sample in combination with the inorganic antimicrobial active ingredient zinc oxide was also prepared. The structures of all the prepared samples were studied by X-ray diffraction, FTIR analysis and, predominantly, by SEM. The very different structure properties of the prepared nanofillers had a fundamental influence on the final structural arrangement of thin PCL nanocomposite films as well as on their mechanical, thermal, and surface properties. As sample PCL/ZnOVER_CPX possessed the best results for antimicrobial activity against examined microbial strains, the synergic effect of CPX and ZnO combination on antimicrobial activity was proved, but on the other hand, its mechanical resistance was the lowest.

Surface sensitive magneto-optical Kerr microscopy completed with the special self-made sample holder is used for studying the magneto-elastic behaviour in the surface of the as-quenched amorphous Fe₇₃Co₁₂B₁₅ alloy. The 10, 5, and 3 mm wide and approximately 34 μm thick ribbons were prepared by the conventional planar flow casting process. The experimental setup allows for a simultaneous application of an external magnetic field in the directions parallel and perpendicular to the ribbon axis and of compression stress from one side of the sample, resulting in tensile stress in opposite side. The distributions of tensile stresses in the measured surface were modelled by the finite element method. The observed changes of the magnetic domains and hysteresis loop anisotropy field under applied stress are evaluated using the Becker–Kersten method. This resulted in the determination of the local surface magnetostrictive coefficient from an area of about 200 μm in diameter. The obtained values ranged between 37–60 ppm and were well comparable with the bulk value presented in the literature.

Three types of commercial austenitic stainless steels, 1.4307 (AISI 304 L), 1.4404 (AISI 316 L) 1.4845 (AISI 310 S) with different chemical compositions, are subjected to severe plastic deformation at room temperature by a unique Dual Rolling Equal Channel Extrusion (DRECE) method. Its impact is evaluated from the viewpoint of microstructure analyses, X-ray diffraction, and macroscopic magnetic properties completed by microscopic Mössbauer characteristics. The study also includes the solution annealing at 950 °C for 0.5 h to follow the recovering austenitic structure and paramagnetic state of steels with the aim to offer more information with respect to new technical applications. The results show the importance of the steel’s chemical composition and microstructure, mainly grain size, on the stability of the austenitic structure closely associated with the paramagnetic behaviour.

Three Fe-based ribbon-type samples prepared by a conventional planar flow casting process are studied from the viewpoint of the amorphous Fe₈₀Si₄B₁₆ and partially surface crystallized Fe₈₀Si₁₀B₁₀, and Fe_80.5Nb_6.9B_12.6, microstructures. Surface magnetic properties are investigated by magneto-optical Kerr microscopy, allowing the measurement of a local hysteresis loop from a selected area on the ribbon surface, and simultaneously, a domain structure corresponding to a definite point at the loop. For an amorphous sample, the changes in the slopes of hysteresis loops are related either to the size of the selected surface area, from which the loop is measured, or to the type, width, and movement of magnetic domains through this area. In the first case, the resizing of the area simulates an effect of changing the diameter of the incident laser beam on the magneto-optical properties of the ribbon. In the latter case, the observed wide-curved and fingerprint domains are responsible for markedly different shapes of the hysteresis loops at lower magnetic fields. If the surface is crystallized, the magnetic properties are more homogenous, showing typical one-jump magnetization reversal with less dependence on the size of the surface area. The magneto-optical experiments are completed by transmission electron microscopy and magnetic force microscopy.

Manganese-based alloys with the composition Mn₂FeZ (Z = Si, Al) have been extensively investigated in recent years due to their potential applications in spintronics. The Mn₂FeSi alloy, prepared in the form of ingots, powders, or ribbons, exhibits either a cubic full-Heusler (L2₁) structure, an inverse-Heusler (XA) structure, or a combination of both. In contrast, the Mn₂FeAl alloy has so far been synthesized only in the form of ingots, featuring a primitive cubic (β-Mn type) structure. This study focuses on the new quaternary Mn₂FeSi_0.5Al_0.5 alloy synthesized from pure Mn, Fe, Si, and Al powders via mechanical alloying. The elemental powders were ball-milled for 168 h with a ball-to-powder ratio of 10:1, followed by annealing at 550 °C, 700 °C, and 950 °C for 8 h in an argon protective atmosphere. The results demonstrate that annealing at lower temperatures (550 °C) led to the formation of a Heusler structure with a lattice constant of 0.5739 nm. Annealing at 700 °C resulted in the coexistence of several phases, including the Heusler phase and a newly developed primitive cubic β-Mn structure. Further increasing the annealing temperature to 950 °C completely suppressed the Heusler phase, with the β-Mn structure, having a lattice constant of 0.6281 nm, becoming the dominant phase. These findings confirm the possibility of tuning the structure of Mn₂FeSi_0.5Al_0.5 alloy powder—and thereby its physical properties—by varying the annealing temperature. The sensitivity of magnetic properties to structural changes is demonstrated through magnetization curves and zero-field-cooled/field-cooled curves in the temperature range of 5 K to 300 K.

The study investigates the influence of pressure-induced plastic deformation on the microstructural evolution, microhardness, and magnetic behavior of AISI 304 and AISI 316L austenitic stainless steels. Samples were subjected to different levels of compressive deformation and subsequently analyzed using optical microscopy, microhardness testing, and vibrating sample magnetometry (VSM). The microstructure after solution annealing consisted of polyhedral austenitic grains with numerous annealing twins, while after deformation, distinct signs of plastic strain were observed within individual grains. The microhardness measured perpendicular to the loading direction increased with the degree of deformation, reaching the highest values in the core of the samples, which confirms the non-uniform distribution of plastic deformation. Magnetic measurements revealed a noticeable increase in both saturation and remanent magnetization after plastic deformation, confirming the presence of deformation-induced α′-martensite. The coercive field decreased for AISI 304 but slightly increased for AISI 316L. The results demonstrate a clear correlation between mechanical strengthening and the magnetic response of austenitic steels subjected to plastic deformation.