Manipulation of morphologies and magnetic properties for Bi4.2K0.8Fe2O9+δ nanostructures

Abstract

In this paper, Bi_4.2K_0.8Fe₂O_9+δ nanostructures with different morphologies, such as dispersible nanobelts, urchin-like and floriated micronanostructures with dendrites in different sizes, were controllably synthesized by a surfactant-free hydrothermal method. The temperatures of the KOH solutions in the co-precipitation step and the hydrothermal reactions had great effects on not only the morphologies but also the magnetic properties of the products. It was found that the low-temperature-fabricated urchin-like samples had a higher magnetization value. The special cores of the urchin-like nanostructures may play a critical role in the enhanced magnetizations and spin-glass dynamic behaviors. These results provide a simple way to manipulate the morphology of low-dimensional Bi_4.2K_0.8Fe₂O_9+δ nanostructures as well as their related magnetic properties.