“…Sol-gel, co-precipitation, inert gas condensation, microemulsion, etc., are commonly used methods to coat nanoparticles for surface modification [13][14][15]. Among them, sol-gel process is a simple chemical method, which has been extensively used for the coating of different nanoparticles with SiO 2 layer [6,12,16]. Magnetic properties of the nanoparticles can also be influenced by preparation technique, preparation conditions, interparticle interactions, particle shape and particle size [17].…”