Structural, magnetic and microwave absorption properties of Ni-doped ZnO nanofibers

ZnO nanofibers (NixZn(1 - x)O with x = 0.03, 0.05, 0.07, 0.09) have been prepared by electrospinning method. The structural, morphological, static magnetic properties and microwave absorption properties are investigated in detail. The as-prepared samples show hexagonal wurtzite structure. However, the lattice constants decrease with the increase of Ni doping cotent, which result in the shrunk of the diameter of nanofibers. The static magnetic properties and microwave absorption properties can be tuned by varying the Ni content. The maximum saturation magnetization is obtained when x = 0.07 due to cation percolation threshold. The dielectric loss properties could be attributed to the dipole polarizations and interface polarization. The magnetic loss properties are mainly caused by natural resonance and exchange resonance. In addition, the networks of NixZn(1 - x)O nanofibers also benefit dissipating electromagnetic energy. The refelection loss (RL) of Ni0.07Zn0.93O nanofibers reaches -2.7 dB at 7.6 GHz and the electromagnetic wave absorption less than -2 dB is found to reach 3.1 GHz for an absorber thickness of 4.5 mm.