Synthesis and magnetic properties of Y 3−xDy xFe 5O 12 nanoparticles

Abstract

Dy 3+-substituted garnet nanoparticles Y 3− x Dy x Fe 5O 12 ( x = 0 , 0.2, 0.4, 0.6, 0.8 and 1.0) were fabricated by a sol–gel method and their crystalline structures and magnetic properties were investigated by using X-ray diffraction (XRD), infrared spectroscopy and vibrating sample magnetometer (VSM). The XRD patterns of Y 3− x Dy x Fe 5O 12 have only peaks of the garnet structure and the sizes of particles range from 37 to 63 nm. Results of VSM show that the saturation magnetization of Y 3− x Dy x Fe 5O 12 ( 0 < x ⩽ 1 ) particles is not only obviously less than pure Yttrium iron garnet, but also decreases with increasing the Dy concentration ( x) in a linear manner. Meanwhile, it is observed that with the enhancement of the surface spin effects, the saturation magnetization rises as the particle size is increased.