Figure 3

SQUID.
(a) Magnetic hysteresis loops recorded at 300 K for 20 nm and 40 nm square nanoparticles. Inset shows the low field region of the hysteresis loop. (b) Magnetic hysteresis loops recorded at 5 K.

SQUID.
(a) Magnetic hysteresis loops recorded at 300 K for 20 nm and 40 nm square nanoparticles. Inset shows the low field region of the hysteresis loop. (b) Magnetic hysteresis loops recorded at 5 K.