Figure 2

SEM images of CoFe 2 O 4 /SrFe 12 O 19 nanofibers with different Co/Sr 2+ molar ratios: (a) 8.0, (b) 5.0, (c) 3.0, (d) 1.8, and (e) 0.8.
SEM images of CoFe 2 O 4 /SrFe 12 O 19 nanofibers with different Co/Sr 2+ molar ratios: (a) 8.0, (b) 5.0, (c) 3.0, (d) 1.8, and (e) 0.8.