LAUSR

We have examined magnetic hysteresis scaling of minor loops for cubic Fe3O4 nanoparticles with particle diameter of 265 nm in order to seek a possible application of the method for characterization of magnetic nanoparticles. While the conventional Steinmetz law fails, a power-law scaling with an exponent of 1.3±0.1 was found to universally hold true between the remanence and hysteresis loss of minor loops below and above the Verwey temperature of ∼ 100 K. A minor-loop coefficient obtained from the power law exhibits a sudden increase with an onset of Verwey transition, followed by a steep increase with decreasing temperature. The increase of the coefficient at Verwey transition is by 390%, being much higher than 260% for major-loop coercivity. There observations demonstrate that a magnetic hysteresis scaling using symmetrical minor loops can be a possible technique for characterizing magnetic nanoparticles due to its sensitivity to materials intrinsic properties and low measurement fields below 1 kOe.