Figure 6: FE-SEM and HR-TEM of co-doped Zn2+ and La3+ ions Fe3O4 nanopowders doped with different La3+ ion molar ratios: (a-b) 0.0 La3+ ion, (c-d) 0.2 La3+ ion, and (e-f) 0.3 La3+ ion, synthesized via co-precipitation route under N2 atmosphere at room temperature.