Size dependence of non-magnetic thickness in YIG nanoparticles

• Pure phase Y3Fe5O12 nanoparticles are fabricated in different particle size by a thermal treatment.
• The size effect on magnetic properties is studied with a core/shell (magnetic/nonmagnetic) model.
• The logarithmic variation of (dead layer thickness)/(particle size) ratio with the particle size is investigated.
• The results of Mossbauer are explained based on the correlation between lattice constant and particle size variation.

This study is focused on particle size dependence of structural and magnetic properties in yttrium iron garnet (Y3Fe5O12) nanoparticles. A series of YIG samples with different particle size were produced by varying the annealing temperatures. The X-ray analysis revealed an inverse correlation between lattice parameter and the crystallite size. The normal distribution is used for fitting the particles size distribution which is extracted from scanning electron micrographs. Also, by using the results of vibrating sample magnetometer, the magnetic diameter was calculated based on Langevin model in order to investigate the variation of dead layer thickness. Furthermore, the observed line broadening in Mössbauer spectra confirmed the increase of non-magnetic thickness due to the reduction of particle size.