Static magneto-optical birefringence of size-sorted γ-Fe2O3 nanoparticlesE. Hasmonay, E. Dubois, J.-C. Bacri, R. Perzynski, Yu. L. Raikher and V. I. StepanovEur. Phys. J. B, 5 4 (1998) 859-867DOI: https://doi.org/10.1007/s100510050512