In this Reply we show that the thermal characteristic of mu(p) increases with increasing temperature remains when size distribution of the nanoparticle assembly has been accounted for. In addition, the antiferromagnetic-like or ferrimagneticlike spin configuration is also required to understand the two-component hysteresis observed in the M(H(a)) curves. The appearance of hysteresis in the low H(a) regime [Fig. 4 of W.-H. Li, C.-W. Wang, C.-Y. Li, C. K. Hsu, C. C. Yang, and C.-M. Wu, Phys. Rev. B 77, 094508 (2008)] indicates the existence of a net spontaneous moment in the nanoparticle, whereas the enlarged hysteresis at the high H(a) regime can be the results of the occurrence of spin reorientation of the core and surface macromoments triggered by the applied magnetic field.
