Facile synthesis and characterization of magnetochromatic Fe3O4 nanoparticles

Abstract

A facile synthetic method for magnetochromatic Fe3O4 nanoparticles (FNPs) with controllable size and optical properties has been fabricated by the combination of an improved solvothermal method and the usage of ultrasonic irradiation in the surface modification step. The improved solvothermal method enables the alteration of the size of nanoparticles (50nm to 180nm) in a competitively convenient way by adjusting the ratio of binary solvents, including diethylene glycol (DEG) and ethylene glycol (EG). In the surface modification step, the short-chain polyacrylic acid (PAA) is added as the surfactant with ultrasound-assisted method. In this research, due to magnetically-driven assembly FNPs forming photonic crystals, the reflection peaks show blue-shift as the magnetic field is increased from 181 to 2479G. In addition, on the basis of the calculation using Bragg’s Law, the thickness of the solvent layer is measured approximately 35nm, which accounts for the magnetochromatic properties as well as excellent dispersion.