Magnetic and Electronic Properties of Zn-Doped Fe3O4 Hollow Nanospheres

Potential applications of Fe3O4 nanostuctures can be enhanced by preparing nanohollow spheres (NHSs) instead of nanoparticles and doping Zn to replace Fe. Detailed temperature-dependent magnetic studies of ZnxFe3-xO4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 1.0) NHSs indicate their increase in saturation magnetization (M-S) with Zn doping, attaining a maximum at x = 0.2 (M-s = 92.52 emu/g at room temperature), due to the replacement of antiferromagnetically coupled Fe-A(3+) ions on the A site by nonmagnetic Zn2+ ions and the transformation of Fe-B(2+) to Fe-B(3+) at the B site for maintaining the charge neutrality. The dynamic magnetic properties, studied by analyzing the real and imaginary parts of ac susceptibility, reveal the spin cluster interaction in our systems. Moreover, the investigation of dielectric properties as a function of temperature over a frequency range of 10 KHz to 100 MHz indicates the reduction in dielectric permittivity and electrical conductivity with increasing Zn content. Enhanced magnetism with a decrease in conductivity, permittivity, and dipolar interaction enables ZnxFe3-xO4 NHSs to be an excellent material for high-frequency and biomedical applications.