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Hafnium dioxide (HfO2) gate dielectrics formed by the atomic layer deposition (ALD) process were fabricated to investigate the flatband voltage shift (ΔVFB) relative to SiO2. It is found that the direction of ΔVFB depends on the Fermi level position in the gate material, which shows respective positive and negative shifts in n-type and p-type metal–oxide–semiconductor field-effect transistors (MOSFETs), regardless of the substrate type. The opposite direction in the flatband voltage shift is attributed to both acceptor- and donor-like interface states existing at the interface between the polycrystalline-silicon (poly-Si) gate and HfO2 dielectric. A model is proposed to explain the effects of poly-Si gate type on the flatband voltage shift in MOSFETs.

Phase separation in La0.67Ca0.33MnO3 thin films was investigated by scanning tunneling microscopy. The correlation between the grain structure and the spatial distribution of the coexisting metallic and insulating phases was evidently established. At temperatures not far below the metal–insulator transition, the spatial variation of the coexisting metallic and insulating phases is susceptible to magnetic field in an irreversible manner. The irreversibility suggests that the metallic percolation paths can be affected randomly by magnetic field. However, the variation becomes insensitive to magnetic field at lower temperatures.

Microscopic grain structures and magnetic properties of Co-doped ZnO-patterned films were studied by combinatorial atomic force microscopy and magnetic force microscopy (MFM) imaging. Whereas Co-doped ZnO was not uniformly magnetized, Co ions were homogeneously doped in the films and substitute from the Zn sites. Most Co:ZnO grains were weakly ferromagnetic (FM) and surrounded by strong FM foamlike grain boundaries networks. No MFM contrast was observed in pure ZnO films grown under similar conditions. The findings clearly demonstrate that defective grain boundaries and magnetic doping have key roles FM properties of diluted magnetic oxides.

The angular dependence of magnetoresistance (MR) of the La0.7Ca0.3MnO3 thin film biepitaxial step junction (BSJ) shows a simple sin2(θ) dependence in the in-plane high-field magnetoresistance, with θ being the angle between the applied field and current. This behavior is similar to the spin-orbit coupling-induced anisotropic magnetoresistance (AMR) commonly observed in transition ferromagnetic metals, except for two salient features. First, the maximum MR in the present case occurs at an oblique angle between the applied field (H) and electric current (I), while it is usually observed to occur when H‖I. Second, the AMR in the plane perpendicular to the film surface displays a remarkable value (Δρ∕ρ∼8%), which is about an order of magnitude larger than that of the in-plane AMR. Such a large AMR cannot be solely explained by spin-orbit coupling effect. We suggest instead that the metallic and ferromagnetic inhomogeneous granules existing in the BSJ region might have acted as the source of spin-polarized sca...