Hybrids, which were composed of the amphiphilic diblock copolymer polystyrene-b-poly(2-hydroxylethyl methacrylate) (PSt-b-PHEMA) and nickel, cobalt, or a nickel-cobalt alloy, were characterized with infrared absorption spectroscopy and ultraviolet-visible (UV-vis) absorption spectroscopy. UV-vis spectroscopy analysis showed that a redshift happened after the PSt-b-PHEMA/ metal-ion complexes were reduced by KBH4. The PSt-bPHEMA /nickel-cobalt alloy hybrids had the biggest redshift [difference of the UV-vis absorption wavelength between (PSt-b-PHEMA)/metal ion complex and (PSt-bPHEMA)/metal hybrids (Delta lambda(m) = 19.9 nm)]. In comparison with the PSt-b-PHEMA/nickel hybrids (Delta lambda(m) = 3.5 nm) and PSt-b-PHEMA/cobalt hybrids (Delta lambda(m) = 9.0 nm). The magnetic properties of PSt-b-PHEMA/metal were studied with vibrating sample magnetometry. The results of magnetic hysteresis loop studies showed that the obtained PSt-b-PHEMA/metal hybrids could be categorized as ferromagnetic materials. The results showed that the magnetic susceptibility decreased with increasing temperature in the range of 150-400 K and increased with increasing temperature above 400 K. (c) 2005 Wiley Periodicals, Inc. J Appl Polyrn Sci 99:2314-2319, 2006