Showing papers by "Akira Fujishima published in 1996"
TL;DR: The magnetization in the ferrimagnetic region below 16 kelvin was substantially increased after illumination and could be restored almost to its original level by thermal treatment and these effects are thought to be caused by an internal photochemical redox reaction.
Abstract: Photoinduced magnetization was observed in a Prussian blue analog, K0.2Co1.4- [Fe(CN)6]·6.9H2O. An increase in the critical temperature from 16 to 19 kelvin was observed as a result of red light illumination. Moreover, the magnetization in the ferrimagnetic region below 16 kelvin was substantially increased after illumination and could be restored almost to its original level by thermal treatment. These effects are thought to be caused by an internal photochemical redox reaction. Furthermore, blue light illumination could be used to partly remove the enhancement of the magnetization. Such control over magnetic properties by optical stimuli may have application in magneto-optical devices.
1,537 citations
77 citations
TL;DR: In this article, photo-induced spin ordering can be rerandomized by thermal treatment and the newly appearing spin on Fe orders the spins on the nearest Ni2+ ions around Fe.
Abstract: Rational design of a magnetic material (nickel nitroprusside) at the molecular level allowed switching of a spin coupling by means of photoinduced metal to ligand charge transfer (MLCT). Before irradiation, spins on Ni2+ are in a disordered state. An illumination at 375 nm induces a MLCT from Fe to NO and forms new spins on Fe and NO. The newly appearing spin on Fe orders the spins on the nearest Ni2+ ions around Fe. In other words, one MLCT aligns five spin sources resulting in the formation of magnetic clusters with S = 5. Furthermore, such a photoinduced spin ordering can be rerandomized by thermal treatment.
52 citations
TL;DR: In this article, a nonroughened evaporated silver film was used as a substrate for a self-assembled monolayer of p-nitrothiophenol, which was then subjected to UV photopatterning.
Abstract: A nonroughened evaporated silver film was used as a substrate for a self-assembled monolayer of p-nitrothiophenol, which was then subjected to UV photopatterning. The photopattern was imaged using surface-enhanced Raman scattering (SERS). To our knowledge, this is the first report of the use of SERS to image a patterned monolayer. Although the nature of the photoproduct is uncertain, it is probable that it is predominantly the azobenzene species.
45 citations
TL;DR: In this article, Raman scattered light from pyridine adsorbed on an electrochemically roughened silver electrode surface was used to image the two-dimensional surface morphology with a spatial resolution of 1 μm.
Abstract: Raman scattered light from pyridine adsorbed on an electrochemically roughened silver electrode surface was used to image the two-dimensional surface morphology with a spatial resolution of 1 μm. The images showed that the spatial distribution and intensity of the surface-enhanced Raman scattered (SERS) light intensity varied to a significant extent over the electrode surface and revealed apparent surface features, specifically, ridges and domes with dimensions on the order of 10 μm. Atomic force microscopic images also showed similar structures. In addtion, the AFM images showed that smaller surface features, on the order of 1−3 μm, were associated with brighter areas in the SERS images. However, the difference in SERS intensities for bright vs dark areas was at most a factor of ∼6, indicating that, even in the dark areas, there was significant surface enhancement. Consistent with this result is the fact that, at still higher magnification, the AFM images in different areas of the electrode showed very s...
32 citations
TL;DR: The surface enhanced Raman scattering effect was used in conjunction with a micro-Raman system to produce an image of a pattern, on an evaporated silver surface, formed by microcontact printing of p−nitrothiophenol (PNTP) as mentioned in this paper.
Abstract: The surface enhanced Raman scattering effect was used in conjunction with a micro‐Raman system to produce an image of a pattern, on an evaporated silver surface, formed by microcontact printing of p‐nitrothiophenol (PNTP). This surface is characterized by roughness on the scale of 50–100 nm. It was confirmed that this type of printing technique forms a self‐assembled monolayer with PNTP. Even without roughening of the silver surface, the surface enhancement provided a high contrast image. The resolution of the resulting image was approximately 1 μm.
19 citations
TL;DR: A series of dye-included metal complex-based magnets, DAMS[MCr (ox)3] (DAMS+ = 4-[2-(4-dimethylaminophenyl)ethenyl]-l-methylpyridinium cation; M2+=Mn2+, Fe2+, Ni2+; ox2- =Oxalate Ion), were synthesized as mentioned in this paper.
Abstract: A series of dye-included metal complex-based magnets, DAMS[MCr (ox)3] (DAMS+ = 4-[2-(4-dimethylaminophenyl)ethenyl]-l-methylpyridinium cation; M2+=Mn2+, Fe2+, Ni2+; ox2- =Oxalate Ion), were synthesized. In these compounds different kinds of metal cations are bridged to each other by ox2- ions. The compounds have a layered-structure and molecules of DAMS+ are enclathrated between the layers. Field-cooled magnetization (FCM) measurement showed that these compounds exhibit magnetic phase transition at 10K, 14K, and 18K respectively.
10 citations
TL;DR: In this paper, the magnetic properties of one-dimensional charge transfer complex between manganese meso-tetraphenylporphyrin (MnTPP) and tetracyanoethylene (TCNE) were investigated as its plate crystals.
Abstract: Magnetic properties of one-dimensional charge transfer complex between manganese meso-tetraphenylporphyrin (MnTPP) and tetracyanoethylene (TCNE) were investigated as its plate crystals. Strong magnetocrystalline anisotropy was observed in the field and the temperature dependences of magnetization. Magnetic phase transition was observed as 24 K and 27 K under 0.5 T of magnetic field along a- and b-axes, and c-axis, respectively. Either temperature was higher than that (18 K) of powder sample reported previously.
4 citations