A study of the size and clustering effects of DyF <subscript>3</subscript> samples.

The magnetic properties of DyF 3 powders with a particle size of 16 nm-7 μm were studied. The saturation magnetization decreases with decreasing particle size. It was shown that magnetic moments are ordered according to the density function of the Lorentz distribution, and the disorder parameter decreases with increasing particle size. A theoretical model is proposed to describe the magnetic properties, taking into account the influence of two mechanisms (clustering and surface layer effect) on the magnetization of DyF 3 powder for the first time. The thickness of the surface layer for this case was determined as 0.5 ± 0.1 nm using the proposed model which is in agreement with the finite-size-scaling theory.