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Transition metal oxides are a class of functional materials widely used in optoelectronics, spintronics, and memory technology. The oxygen stoichiometry of these oxides plays a vital role in determining their electronic, optical, and thermal properties. Post-growth annealing in ozone has shown to be effective in modifying these properties. Here, we choose NiO, an antiferromagnetic Mott insulator in perfect stoichiometry, as an example to show that its stoichiometry can be tuned continuously in a broad range by the control of the oxidation power during growth or a post-growth topotactic reduction process. The bandgap of the as-processed NiOx films was modulated in accordance with their resistivity, lattice constant, and Ni chemical valence. This method can be readily applied to other transition metal oxides for the optimization of their properties. [ABSTRACT FROM AUTHOR]

Immunomagnetic reduction assay is used to quantitatively detect bio-molecules. Many reports show that the to-be-detected bio-molecular concentration dependent reduction in the alternative-current (ac) magnetic susceptibility of a reagent is governed by the logistic function, which is a four-parameter function. One of the parameters relates to the increase in the rate of the magnetic reduction signal when the concentration of to-be-detected bio-molecules is increased. Theoretically, this parameter is attributed to the clustering associations between to-be-detected bio-molecules and labeling particles in the reagent. In an immunomagnetic reduction assay, the bioactive labeling particles are anti-body-functionalized magnetic nanoparticles. However, there is no detailed information about the effect of the clustering associations on this parameter. In this work, the clustering association is manipulated by controlling the concentrations of anti-body-functionalized magnetic nanoparticles in the reagent. The experimental results show that higher values for this parameter are obtained with concentrated anti-body-functionalized magnetic nanoparticles in the reagent. This implies that particle clustering is enhanced by an increase in the concentration of the bio-functionalized magnetic particles. It is also demonstrated that the particle clustering effect dominates the increased rate of the magnetic reduction signal. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated the carbon impurity effects on the intermixing behavior of GaAs/AlAs multiple quantum wells grown by molecular-beam epitaxy using photoluminescence measurements. Annealing of the multiple-quantum wells; Experimental details; Results and discussion; Conclusions.

Presents a study that investigated the silicon implantation efficiency, the silicon depth profile and the vacancy formation for silicon-implanted gallium arsenide crystals. Background on the implantation of impurity atoms in semiconductor materials; Discussion on the incident angle dependence of the implantation depth of the silicon ions and the vacancies of gallium and arsenic.

Deals with a study which investigated the surface chemical properties of a gallium arsenide (GaAs) layer grown by molecular beam epitaxy using photoluminescence and photoreflectance measurements. Advantages of GaAs compound semiconductors; Background on studies regarding Fermi level pinning for the fabrication of GaAs field effect transistors; Significance of the findings.