427489.fig.004a
(a)
427489.fig.004b
(b)
427489.fig.004c
(c)
Figure 4: The hysteresis loops of (a) Ni and (b) Ni@C nanoparticles at room temperature. (Magnification of hysteresis loop for Ni@C is represented.) (c) Initial magnetization curve for Ni@C nanoparticles at room temperature.