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In the present work, 2.4 nm gold nanoparticles (Au NPs) are uniformly dispersed on mesoporous titania thin films which are structurally tuned by controlling the calcination temperature. The gold content of the catalyst is as high as 27.8 wt %. To our knowledge, such a high loading of Au NPs with good dispersity has not been reported until now. Furthermore, the reaction rate of the gold particles is enhanced by one order of magnitude when supported on mesoporous titania compared to non-porous titania. This significant improvement can be explained by an increase in the diffusivity of the substrate due to the presence of mesopores, the resistance to agglomeration, and improved oxygen activation.

We investigate magnetotransport properties of thin (Ga,Mn)Sb layers in a field-effect structure. By changing the hole concentration p in the channel by applied electric fields, we establish the relationship between the Curie temperature TC and p, which shows γ of 1.3–1.6 in TC ∝ pγ. The exponent γ is several times larger than γ ∼ 0.2 reported previously for (Ga,Mn)As. Analyses based on the p-d Zener model taking into account of non-uniform hole distribution in the channel shows that the lager γ is explained by the presence of hole accumulation at the interface of (Ga,Mn)Sb and the gate insulator.

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