Misc

Nanoparticles can be broadly defined as a material consisting of hundreds to a few thousand atoms with the size below 20 nm. Nanoparticles have been paid considerable attention, due to the application ranging from magnetic recording media, catalysts, and the field of photonics and bioengineering. Our research group has been focused on the development of a novel magnetic nanoparticle where the photomagnetic effect is present. Herein, we introduce our recent research topics about post-functionalization of the room-temperature ferromagnetic FePt nanoparticle via surface modification. In the photochromic molecules-modified FePt nanoparticles, the room-temperature photomagnetic effect was present with high efficiency. Moreover, in the polymer-modified FePt nanoparticles, heat generation under an alternating magnetic field was present through the hysteresis-loss mechanism.

Phototunable magnets have been of interest from the viewpoint of the photon-mode high-density information storage media. However, so far, there have been reported a limited number in successful preparation of such compounds due to an unestablished strategy. Along this line, we have proposed the concept "incorporation of photochromic molecules to magnetic system based on the organic-inorganic hybrid". Herein, we introduce successful examples of such photochromic magnetic systems, in which a montmorillonite nanosheet are used as a building block. Also, we describe a very recent result of a reactor-dependent photochromism on spiropyran-montmorillonite hybrids.