Background: Among the mixed transition metal oxides, ZnFe2O4 as a binary metal oxide
with a spinel structure has a wide range of application prospects in materials science and technology.
The microstructure, energy band structure, optical properties and magnetic properties of ZnFe2O4 can
be modified by element doping.
Objective: In this work, the influences of Ni doping upon the structure, morphology, optical and
magnetic properties of ZnFe2O4 were studied.
Methods: Pure and Ni-doped Zn1-xNixFe2O4 nanoparticles with different concentration (x = 0, 0.1,
0.3 and 0.5) were successfully synthesized by hydrothermal method. XRD, HRTEM, XEDS, UV–
vis, FT-IR and VSM were utilized to investigate the Zn1-xNixFe2O4 nanocrystals samples.
Results: The experimental results show that all Zn1-xNixFe2O4 nanoparticles have cubic spinel structure
with good crystallization. Ni2+ successfully substituted for the lattice site of Zn2+ and generated
single-phase ZnFe2O4 without other impurity phases. After Ni doping, the grain size distribution
increased, the bandwidth increased and ferromagnetism increased.
Conclusion: The crystalline size increased as Ni concentration increased, while its the lattice constant
occurshrink expansion. The energy band gap of Zn1-xNixFe2O4 nanocrystals increased as Ni
concentration increased, and blue shift occurred compared to that of the pure ZnFe2O4. Pure ZnFe2O4
nanocrystals showed superparamagnetic properties, while the doped Zn1-xNixFe2O4 samples have
obvious ferromagnetic properties at room temperature.