Comparing the magnetic property of shell thickness controlled of Ag-Ni core-shell nanoparticles

In this paper, we studied the critical diameter of superparamagnetic core-shell particles. One pot method and microwave-assisted technique were used to synthesize Ag-Ni core-shell nanoparticles with diameters of 10 nm and 30 nm. From the experimental results of hysteresis (M-H curves) and temperature dependent magnetization (M-T curves), the theoretical critical diameter does not agree with the experimental observation of the core-shell structure. Furthermore, the blocking temperature equation should be reconsidered.