Synthesis and Magnetoelectric Properties of NiFe$lt;inf$gt;2$lt;/inf$gt;O$lt;inf$gt;4$lt;/inf$gt;-BiFeO$lt;inf$gt;3$lt;/inf$gt; Nanotubes

Abstract

xNFO-(1-x)BFO (NFO-BFO) nanotube arrays were fabricated by means of Sol-Gel method utilizing nanochannel alumina as templates. Scanning electron microscopy study revealed that the outer diameter of nanotube was about 70 nm, and the internal diameter was about 50 nm, the length was about 80 m. Meanwhile, ferroelectric phase BFO of perovskite structure and ferromagnetic phase NFO of spinel structure were formed through self-assembly growth in X-ray diffraction patterns. Significant ferromagnetic and polarized characteristics of nano- tube arrays were demonstrated by means of magnetic and ferroelectric measurement at room temperature, and the direction of easy magnetization was along the long axis. With increasing ratio of NFO, the magnetic and polarized properties of nanotube arrays increased gradually. The calculation results of NFO's ferromagnetic contribution in- dicated that magnetoelectric coupling effect existed in the NFO-BFO composite nanotube arrays.