We have carried out a detailed study of the magnetic switching in square lattice cobalt antidot arrays with periods ranging from $2\mu \mathrm{m}$ down to $200\mathrm{nm}$ (antidot $\text{size}=\text{antidot}$ separation). Magneto-optical Kerr effect measurements show first a small change in the magnetization due to a reversible rotation of the magnetic spins in the antidot rows, followed by a large change due to reversal of the antidot array columns parallel to the applied field. Employing x-ray photoemission electron microscopy and transmission x-ray microscopy, the latter irreversible process was observed as a nucleation and propagation of discrete domain chains. The propagating chain ends are blocked by perpendicular chains present in the antidot rows via various mechanisms revealed by micromagnetic simulations.

The optical properties of hydrogen exposed palladium (Pd) and palladium oxide (PdO) thin films are calculated from reflectance and transmittance measurements in the visible and near infrared range (400–900nm). The time evolution of the films’ optical constants when exposed to hydrogen is shown. The real part of palladium’s refractive index increases about 5%, whereas the imaginary part decreases nearly 15% after hydrogen absorption. The Pd films’ resistance also increased upon hydrogen absorption, as expected. Pd oxide reduces to metallic palladium upon hydrogenation, showing a dramatic change in all the properties. The palladium films’ resistance initially decreases after a first exposure to 5Torr of hydrogen, and this is tentatively explained by the reaction of hydrogen with impurities trapped in the films.

Dipolar and quadrupolar susceptibility measurements are reported for the molecular glass system ${\left(\mathrm{KBr}\right)}_{1-x}{\left(\mathrm{KCN}\right)}_x$ covering a wide range of frequencies. The results allow a direct comparison of the dipolar and quadrupolar anomalies and demonstrate unambiguously that the freezing in of the dipolar and quadrupolar degrees of freedom occurs at different temperatures.

Using high-resolution ellipsometry and stray light intensity measurements, we have investigated during successive heating-cooling cycles the optical thickness and surface roughness of thin dotriacontane (n-C32H66) films adsorbed from a heptane (n-C7H16) solution onto SiO2-coated Si(100) single-crystal substrates. Our results suggest a model of a solid dotriacontane film that has a phase closest to the SiO2 surface in which the long-axis of the molecules is oriented parallel to the interface. Above this “parallel film” phase, a solid monolayer adsorbs in which the molecules are oriented perpendicular to the interface. At still higher coverages and at temperatures below the bulk melting point at Tb=341 K, solid bulk particles coexist on top of the “perpendicular film.” For higher temperatures in the range Tb<TTs, a uniformly thick fluid film wets to the parallel film phase. This structure of the alkane/SiO2 interfacial region differs qualitatively from that which occurs in the surface freezing effect at the bulk alkane fluid/vapor interface. In that case, there is again a perpendicular film phase adjacent to the air interface but no parallel film phase intervenes between it and the bulk alkane fluid. Similarities and differences between our model of the alkane/SiO2 interface and one proposed recently will be discussed. Our ellipsometric measurements also show evidence of a crystalline-to-plastic transition in the perpendicular film phase similar to that occurring in the solid bulk particles present at higher coverages. In addition, we have performed high-resolution ellipsometry and stray-light measurements on dotriacontane films deposited from solution onto highly oriented pyrolytic graphite substrates. After film deposition, these substrates proved to be less stable in air than SiO2.

The elastic shear constant and the internal friction of three mixed crystals ${\left(\mathrm{KBr}\right)}_{1-x}{\left(\mathrm{KCN}\right)}_x$ have been determined from the resonance of a torsion pendulum in the ${10}^2$-Hz range. Two glass-forming samples ($x=0.20,0.50\mathrm{}$) and one sample ($x=0.75\mathrm{}$) which orders ferroelastically have been investigated. Two regimes of loss have been observed; the primary one is related to domain-wall motion, the secondary one to dipolar reorientations.