Bivalve shells exhibit extreme mechanical resistance despite using a minimal amount of material. The shells thus represent an inspiration and a source of information for environmental, geological, and engineering sciences. In this study, two species of freshwater shells from the Unionidae family, collected in the Czech Luznice River, were investigated with respect to their crystallographic preferred orientation by means of X-ray and neutron diffraction. The observed texture was found to be of a strongly uniaxial type, with the strength increasing along the shell growth direction. The c-axis of aragonite does not change during growth and its alignment remains perpendicular to the outer surface of the shell
Evolution ice diffraction patterns in mixtures of D2O with quartz sand of three different grain coarseness (100–600, 300–800 and 600–1200 μm) were studied under various temperature regimes by means of neutron diffraction method. The studied structural parameters and characteristics involved the phase composition of specimens, Ih D2O ice lattice parameters, and crystallographic texture of the present phases. Variations in the ice crystallographic texture during the repeated freezing and thawing were observed for all tested sample types, showing an intermittent enhancement of ice and quartz texture indices accompanying the start of specimens cooling. Formation of radial internal stresses is demonstrated by the observed split of (002) and (100) diffraction maxima of ice. Estimated mean internal radial stress values are calculated.
Investigation of high-entropy alloys in form of bulk samples as well as thin films is currently one of the fastest growing areas in the study of metal alloys. In this paper, a bulk sample of FeNiCoCuCr high-entropy alloy ingot with equimolar composition is prepared by the laboratory arc melting method under an argon atmosphere and used as a source target for deposition of thin films on Si (111) single-crystalline substrates using a novel ionized jet deposition method. The morphology, chemical composition, and real crystalline structure of the target and the prepared layers were characterized by scanning electron microscopy, atomic force microscopy, energy-dispersive X-ray spectroscopy, and X-ray and neutron diffraction methods. Transfer coefficients characterizing the mass transport between the target and the grown film were calculated for each of the constituting metallic elements as the ratio of the atomic concentration found in the prepared film divided by its concentration in the deposition target. The dependence of the obtained transfer coefficients on the IJD acceleration voltage is discussed with respect to the main physical and geometric parameters of the deposition process, and their correlations with the cohesive energy of the elements forming the HEA are proposed.