Self-assembling ε-Fe2O3/SiO2 nanoparticles to nanoflakes with paramagnetic-class properties via a milling-etching route

Abstract

In this work, the milling-etching route is designed to synthesize nanoflakes with high-content ε-Fe2O3 phase, which is environmental friendly and more desirable for energy-efficient mass production of ε-Fe2O3 phase than conventional thermal treatment methods. More strikingly, this product conforms to the characteristics of paramagnetic-class properties, and our study shows that the unique property derived from ε-Fe2O3 phase is intimately related to large lattice strain and a few of small grains of ε-Fe2O3 based on Rietveld method and the law of approach to saturation. Relaxivities confirm the paramagnetic-class product has the potential to become a candidate as contrast agent in magnetic resonance imaging application filed. Our work not only sheds light on the preparation of ε-Fe2O3 phase, but also enables a new insight into the development of functional ε-Fe2O3 material in practical magnetically-relevant applications.