Size-Selective Precipitation and Aggregate Reduction of FePt-Based Nanoparticles

Abstract EN

Magnetic nanoparticles with a narrow size distribution are desirable for applications in ultra-high density data storage and biomedicine.

In this work, the size-selective precipitation and aggregate reduction were combined to classify superparamagnetic iron platinum- (FePt-) based nanoparticles.

The size-selective precipitation was implemented with the variation in the amount of ethanol.

In the first condition, the ratio of ethanol-to-nanosuspension of 3 : 4 was used in the precipitation twice.

By contrast, the second condition employed the ratios of ethanol-to-nanosuspension of 4 : 4 in the first precipitation and 5 : 4 in the second precipitation.

The first precipitation successfully sorted out the aggregated particles, and the second precipitation collected particles with a narrow size distribution.

The increase in ethanol enhanced the monodispersity of nanoparticles as shown by transmission electron microscopy (TEM) images and size distribution curves.

In addition, large aggregated by-products from the precipitation stage were sonicated with the addition of surfactants.

The increase in ultrasonic power reduces the aggregation, but the longer sonication led to an uneven distribution.