Lead-free ceramics of Na0.5K0.5Nb1-xSbxO3 (NKNS) and Na0.5K0.5Nb1-xSbxO3 + 0.5 mol%MnO2 (NKNS + 0.5 mol%MnO2) (0 < x < 0.06) ceramics were prepared by a conventional solid-state hot pressing method. The ceramics possess a single-phase perovskite structure with orthorhombic symmetry. Microstructural examination revealed that Mn doping of NKNS leads to improvement of densification. The cubic-tetragonal and tetragonal-orthorhombic phase transitions of NKNS shifted to higher and lower temperature, respectively after introduction of Mn ion. Besides, ferroelectric and piezoelectric properties were improved. The results were discussed in term of difference in both ionic size and electronegativity of Nb5+ and Sb5+ and improvement of densification after Mn ion doping.

In this work, vacuum hot pressed Ni-Mn-Sn-In Heusler alloys with different concentration of In (0, 2 and 4 at.%), were investigated. The magneto-structural behaviour and microstructure dependencies on chemical composition and on heat treatment were examined. It was found that the martensite start transformation temperature increases with growing In content and to a lesser extent with increasing temperature of heat treatment. The high energy X-ray synchrotron radiation results, demonstrated that both chemical composition as well as temperature of heat treatment slightly modified the crystal structures of the studied alloys. Microstructural investigation performed by transmission electron microscopy confirmed chemical composition and crystal structure changes in the alloys.

Magnetic microstructure in the as suction cast Fe ₆₉B ₂₀Nb ₂Hf ₂Si ₂Y ₅ alloy was revealed by combined Lorentz-TEM and LM-STEM DPC analysis. The thin foil of the alloy was found to be composed primarily of the amorphous phase with few dendritic structures. Magnetic domains were found large in the µm range with an average domain wall width of 52 nm. The magnetic domain boundaries are easily mobile, what was confirmed by in situ applied magnetic field. The LM-STEM DPC complements the Lorentz-TEM analysis by providing details on the intensity and spatial distribution of the magnetization vector within the domains.

Crystals of PbTiO3 and 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 were obtained by the flux growth method whereas crystals of (Na0.5Bi0.5)TiO3 were growth by the Czochralski method. Raman spectroscopy and polarized light microscopy were performed at room temperature. The Raman spectra of 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 shown significant changes comparing to the base materials PbTiO3 and (Na0.5Bi0.5)TiO3. A domain structure was investigated by use polarized light microscopy. Dielectric permittivity measurements were carried out in the temperature range from 20°C to 550°C and a frequency from 1 kHz to 1 MHz. These showed higher dielectric permittivity for the crystals 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 than the source materials PbTiO3 and (Na0.5Bi0.5)TiO3.

The high value of dielectric constant makes it possible to applied 0.9PbTiO3-0.1(Na0.5Bi0.5)TiO3 as efficient dielectric medium in a capacitors. The small size of the domain structure with the easy possibility of switching by application of an external electric field, give opportunities to apply these materials to FRAM memory applications. Moreover, the high sensitivity of these materials to the surrounding gases e.g. ammonia, chlorine, hydrogen, etc., allows the construction of sensor devices.

This study aimed to develop Fe/Al multilayered metallic/intermetallic composites produced by hot pressing under an air atmosphere. Analyses were carried out on the composite plates made up of alternatively situated sheets of AA1050 aluminum alloy and DN04 low carbon steel, which were annealed at 903 K for 2, 5, and 10 h. Annealing was performed to obtain reaction layers of distinct thickness. The samples were examined using X-Ray diffraction and scanning and transmission electron microscope equipped with an energy-dispersive X-Ray spectrometer. To correlate the structural changes with mechanical properties, microhardness measurements in near-the-interface layers were performed. All the reaction layers grew with parabolic kinetics with η-Al5Fe2 intermetallic phase as the dominant component. After annealing for 5 and 10 hours, a thin sublayer of θ-Al13Fe4 phase was also detected.

In the present work, we performed the ultra-rapid annealing (URA) process for amorphous Fe78Ni8B14 melt-spun ribbons in order to obtain fine excellent microstructure assuring the best soft magnetic properties. Several microscopic methods mainly based on transmission electron microscopy (TEM) and Lorentz TEM (L-TEM) were applied for detailed studies of the microstructure and magnetic domains structure. The investigation revealed that the optimized parameters of the URA process (500°C/0.5-5 s) lead to outstanding soft magnetic properties. A mixture containing close to 50% amorphous phase and 50% α-Fe nanocrystals of size up to 30 nm has been already obtained after annealing for 3 s. These annealing conditions appear to be the most suitable in terms of microstructure providing the best magnetic properties.