Abstract: The nanostructure ferrites of two-phase ZnFe₂O₄/Fe₂O₃ were prepared by the sol-gel method.
The structure was analyzed by X-ray diffraction (XRD) and high-resolution electron microscope (HREM). The
results indicate that two-phase ferrite is the necessary condition to form tunneling structure. Non-Ohmic character
of I-V curve and magnetoresistance effect of two-phase ferrite also show tunneling character. The tunneling
structure was directly observed by HREM in two-phase ferrite that insulating layer of α-Fe₂O₃
located in interface between ferrets. Approved deeply by phase-transformation dynamics, crystallization of α-Fe₂O₃
is controlled by the interface or surface of ZnFe₂O₄ crystallite.

Key words: ferrite, tunneling structure, dynamics, ZnFe₂O₄