Room-temperature ferromagnetism is observed in (110) oriented ZnO films made from targets containing 5 at. % of Sc, Ti, V, Fe, Co, or Ni, but not Cr, Mn, or Cu ions. There are large moments, $2.6{\mu }_B$ and $0.5{\mu }_B/\mathrm{\text{dopant atom}}$ for Co- and Ti-containing oxides, respectively. There is also a moment of $0.3{\mu }_B/\mathrm{S}\mathrm{c}$. Magnetization is very anisotropic, with variations of up to a factor of 3 depending on the orientation of the applied field relative to the substrate. Results are interpreted in terms of a spin-split donor impurity-band model, which can account for ferromagnetism in insulating or conducting high-$k$ oxides with concentrations of magnetic ions that lie far below the percolation threshold. Magnetic moments are associated with two-electron defects in the films as well as unpaired electrons of the $3d$ ions.

Spectroscopic ellipsometry (SE) characterization of layered transition metal dichalcogenide (TMD) thin films grown by vapor phase sulfurization is reported. By developing an optical dispersion model, the extinction coefficient and refractive index, as well as the thickness of molybdenum disulfide (MoS₂) films, were extracted. In addition, the optical band gap was obtained from SE and showed a clear dependence on the MoS₂ film thickness, with thinner films having a larger band gap energy. These results are consistent with theory and observations made on MoS₂ flakes prepared by exfoliation, showing the viability of vapor phase derived TMDs for optical applications.

Fast electrons produced by the irradiation of plane-layered targets with 20-J, 100-ps, ${10}^{15}$-W.${\mathrm{cm}}^{-2\mathrm{}}$, neodymium-laser pulses have been diagnosed by the $K\alpha$ emission which they cause at various depths in the targets. The fast-electron energy spectrum and absolute energy deposition (target preheat) are measured.

Conical refraction was produced by a transparent biaxial crystal of KGd(WO ₄ ) ₂ illuminated by a laser beam. The ring patterns at different distances from the crystal were magnified and projected onto a screen, giving rings whose diameter was 265 mm. Comparison with theory revealed all predicted geometrical and diffraction features: close to the crystal, there are two bright rings of internal conical refraction, separated by the Poggendorff dark ring; secondary diffraction rings decorate the inner bright ring; as the distance from the crystal increases, the inner bright ring condenses onto an axial spot surrounded by diffraction rings. The scales of these features were measured and agreed well with paraxial theory; this involves a single dimensionless parameter ρ ₀ , defined as the radius of the rings emerging from the crystal divided by the width of the incident beam. The different features emerge clearly in the asymptotic limit ρ ₀ ≫1; in these experiments, ρ ₀ =60.

The magnetic, transport, and structural properties of $({\mathrm{La}}_{\mathrm{0.1}}{\mathrm{Sr}}_{\mathrm{0.3}}{\mathrm{)MnO}}_{\mathrm{3}}$ films deposited on MgO (001) are reported as a function of thickness and substrate temperature. The substrate temperature is fundamental in determining the structural properties and a deviation from the optimum temperature (680 °C) leads to grain boundaries and an imperfect (001) texture. Films with different thicknesses were deposited at the optimum deposition temperature. Magnetization and resistivity measurements on these films are interpreted in terms of magnetic and electric “dead” layers. The electric dead layer is an insulating layer approximately 4 nm thick while the magnetic dead layer is a region of weakly coupled noncollinear spins approximately 10 nm thick at each interface.