Solid State Phenomena Vol. 112

Abstract: Ferromagnetic, intermetallic compound Fe3Al exhibits DO3-type crystal structure. There are two non-equivalent types of iron with different chemical neighbourhood – (A,C) and B sublattices. As a consequence of the different nearest environments of the iron atoms at these sites the different electronic and magnetic properties connected with these positions are observed. The aim of our research is to investigate the influence of the local surrounding of the iron on its magnetic moment and hyperfine field in compound Fe3-xMnxAl where iron is substituted by manganese.

Abstract: Directional Compton profiles of single crystal of hcp magnesium have been measured with scattering vectors along the [10 10], [1120] and [0001] directions in reciprocal space (special directions ΓΜ, ΓΚ, ΓΑ) using high-energy (662 keV) gamma radiation from a 137Cs isotope source. The experimental data were compared with corresponding theoretical Korringa-Kohn-Rostoker (KKR) calculations. The directional difference profiles, both experimental (of medium resolution) and theoretical ones, show very small anisotropy of the electron momentum density in magnesium, 2-3 times lower than in zinc and cadmium single crystals, significantly lower than observed in cubic metals. This small directional effect is in good agreement with Compton 60-keV energy experiments and positron annihilation data presented by other authors.

Abstract: The hydrogen influence on the microstructure of the austenitic-ferritic Cr22-Ni5-Mo3 stainless steel was investigated. Cathodic hydrogen charging was performed electrochemically from aqueous solution of 0.1M H2SO4 with hydrogen entry promoter addition. The aim of this study was to reveal microstructural changes appearing during the hydrogen charging and particularly to clarify the occurrence of phase transformations induced by hydrogen. The specific changes in both phases of steel were observed. In the ferritic phase, strong increase of dislocation density was noticed. Longer time of hydrogen charging leaded also to the strips and twin plates formation in ferrite phase. In the austenitic phase, the generation of stacking faults, followed by the formation of α' martensite was remarked.

Abstract: The simplest equation of state compatible with the Widom and Griffiths scaling hypothesis have been built for the uniaxial ferroelectrics TGS and MAPCB. The explicit forms have been found of the scaling invariants deduced from the curves of the electric susceptibility measured in a constant biasing field. Smooth and sharp inflection points of the susceptibility curve in the vicinity of the critical temperature have been classified. The invariants and the inflection points have been used to determine critical parameters of TGS and MAPCB.