In this paper, we investigated the electro-optical properties of the dilute magnetic polymer dispersed liquid crystals (PDLCs) prepared with the liquid crystal colloids containing low concentrations of γ-Fe2O3 nanoparticles. The doped nanoparticles have hardly changed the morphology of PDLCs, but they have significantly changed the threshold voltage, saturation voltage, and contrast ratio of PDLCs. Such changes result from ionic adsorption in competition with the concentration of the nanoparticles. When the concentration of the nanoparticles was...