Size-dependent spin-reorientation transition in Nd2Fe14B nanoparticles

TL;DR

This study investigates how the spin-reorientation transition temperature in Nd2Fe14B nanoparticles varies with particle size, revealing a significant decrease in transition temperature as particle size diminishes, using magnetic susceptibility measurements.

Contribution

It demonstrates the size-dependent behavior of spin-reorientation transition temperature in Nd2Fe14B nanoparticles, a novel insight for magnetic nanoparticle research.

Findings

Tsr decreases with reducing particle size

300 nm particles have lower Tsr than raw materials

20 nm particles show a significant Tsr decrease

Abstract

Nd2Fe14B magnetic nanoparticles have been successfully produced using a surfactant-assisted ball milling technique. The nanoparticles with different size about 6, 20 and 300 nm were obtained by a size-selection process. Spin-reorientation transition temperature of the NdFeB nanoparticles was then determined by measuring the temperature dependence of DC and AC magnetic susceptibility. It was found that the spin-reorientation transition temperature (Tsr) of the nanoparticles is strongly size dependent, i.e., Tsr of the 300 nm particles is lower than that of raw materials and a significant decrease was observed in the 20 nm particles.