Electron microscopic studies of Langmuir–Blodgett films of CoFe2O4 nanocrystallites

The preparation of ultra-thin films of CoFe2O4 nanocrystallites is reported. TEM images of them showed two-dimensional assembly of particles, demonstrating the uniformity of these nanocrystallites. The formation of Langmuir monolayer of the surface coated CoFe2O4 nanocrystallites with oleate at the air/water interface and its stability were studied with a pressure-area isotherm curve. Surface pressure versus surface area isotherms and TEM studies demonstrated that increasing surface pressure resulted in a transition from well-separated domains of nanocrystallites complex to well-compressed, mono-particulate layers and, ultimately, to multi-particulate layers.