Formation of palladium hydride nanoparticles in Pd/C catalyst as evidenced by <Emphasis Type="Italic">in situ</Emphasis> XAS data

X-ray absorption spectroscopy was used to investigate the formation of palladium hydride upon treatment of metallic Pd nanoparticles 0.9–2 nm in size supported on carbon-carbonaceous material SIB UNIT? with hydrogen. Nanoparticles with the size as small as 0.9 nm can still form hydride PdH. Changes in the chemical composition of gaseous medium cause a reversible transformation of metallic palladium nanoparticles to palladium hydride nanoparticles with tentative stoichiometry PdH_0.6.     

Magnetization curves for non-elliptic cylindrical samples in a transverse field

Using recent results for the surface current density on cylindrical surfaces of arbitrary cross-section producing uniform interior magnetic field and an assumed set of flux-fronts, solutions of Bean’s critical state model for cylindrical samples with non-elliptic cross-section are presented. Magnetization hysteresis loops for two cross-sections with different aspect ratios are obtained. A comparison with some exact results shows the limitations of this approach.