| 研究実績の概要 |
Mesoporous HfO2 thin films (around 20 nm thick) were fabricated by sol-gel-based spin-coating process at 600 oC to realize the ion conducting media for the ionics (e.g. Na+ and K+ for rechargeable ion batteries) for battery application.. Another film of aluminum metal (10 nm thick) was deposited by DC sputtering to soak into the mesoporous to control the conductivity. The obtained mesostructured HfO2/Al2O3 films show rather good conductivity which is enough for bias for ion conduction. At the meantime, among all the thin films the mesostructured HfO2/Al2O3 composite thin films showed the smallest Nyquist arc diameter in 1 M KOH electrolyte, implying lower impedance at the electrode/electrolyte interface, reflecting better ions diffusion and movement.
Also we have developed a mesostructured HfO2/Al2O3 composite thin films with much reduced leakage current compared to HfO2 or HfO2/Al thin films.
We have reported simple chemical route for preparation of polycrystalline Ni-Co PBA thin films on the surface of silicon wafers. Several kinds of homogeneous pyramidal structures formed on the surface. The thin films showed paramagnetic properties which may allow applications of these materials in molecular spintronic devices. Our thin films did not show a negative magnetization compared to the previously reported PBAs thin films. This method could be extended for demonstrating multiferroic thin films by forming the multilayered or heterostructures for electric applications in the future.
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