Figure 6.

Hysteresis loops (A) of Fe₃O₄nanocages (a) and γ-Fe₂O₃Nanocages (b); Photographs (B) of the Fe₃O₄nanocages and γ-Fe₂O₃nanocages (dispersed in ethanol solution) before and after magnetic separation by an external magnetic field (this magnet takes from the MSS)