Designed magnetic multilayer thin films fabricated via the layer-by-layer assembly of polycyanofullerenes

The layer-by-layer self-assembly technique was used to fabricate a series of multilayer thin films with poly[4′-(4-methacryloyphenyl)-2,2′:6′,2″-terpyridine] (PmPhtpy), polycyanofullerenes, and transition metals (Ni 2+ and Co 2+ ). The polymer PmPhtpy was prepared by free-radical polymerization, and this was confirmed by Fourier transform infrared (FTIR) and 1 H-NMR spectroscopy. The polycyanofullerenes, which were characterized by FTIR, ultraviolet–visible (UV–vis), and 13 C-NMR spectroscopy, was synthesized via the bromination of fullerene and then substitution with a nucleophilic reagent [potassium cyanide (KCN)]. The optical properties of the films were measured by attenuated total reflection infrared and UV–vis spectroscopy, and the results indicate that the driving force of the fabrication of the multilayer film was the coordination interaction. The magnetic behavior was examined as a function of the magnetic field strength at 5 K and the temperature (5–300 K). The magnetic hysteresis loops of the films showed a typical S shape at 5 K; this suggested soft ferromagnetic properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40681.