Magnetic and Optical Properties of γ-Fe2O3 Nanocrystals

γ-Fe2O3 nanocrystals with a mean radius of 4.2 nm have been synthesized in a polymer matrix by an ion exchange and precipitation reaction. Magnetization and susceptibility data from experiment and computer simulations indicate that the system is superparamagnetic. The optical absorption edge is red shifted with respect to that of an epitaxially-grown single-crystal film of γ-Fe2O3. The red shift is attributed to lattice strain in the small particles.

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