Saturation magnetic properties of Y3−xRexFe5O12(Re: Gd, Dy, Nd, Sm and La) nanoparticles grown by a sol–gel method

Re3+-substituted garnet nanoparticles Y3−xRexFe5O12 (Re = Gd, Dy, Nd, Sm and La) were fabricated by a sol–gel method .The XRD patterns of all samples have only peaks of the garnet structure and the sizes of nanoparticles rang from 34 to 69 nm. Results of VSM show that the saturation magnetization of Y3−xGdxFe5O12, Y3−xDyxFe5O12 and Y3−xSmxFe5O12 nanoparticles decrease evidently as the Re3+ concentration (x) is increased. The saturation magnetization of Y3−xNdxFe5O12 and Y3−xLaxFe5O12 increases firstly and then decreases as the Re3+ concentration (x) is increased. In the meanwhile, it is observed that may be due to the enhancement of the surface spin effects, the saturation magnetization rises as the nanoparticle size is increased.