Preparation of a Vast CoFe₂O₄ Magnetic Monolayer by Langmuir-Blodgett Technique

The preparation of ultrathin films of CoFe₂O₄ nanocrystallites is reported. TEM images of them showed 2-dimensional assembly of particles, demonstrating the uniformity of these nanocrystallites. The formation of a Langmuir monolayer of the surface coated CoFe₂O₄ nanocrystallites with oleate at the air/water interface and its stability were studied with pressure-area isotherm curves and Brewster Angle Microscope (BAM) images. Surface pressure vs surface area isotherms and TEM studies demonstrated that the increasing surface pressure resulted in a transition from a complex with well-separated domains of nanocrystallites to wellcompressed, monoparticulate layers, and, ultimately, to multiparticulate layers.