200 250 300 350 400 0 5000 10000 15000 20000 dotted lines represent the fit with Curie Weiss law (equation 1) solid lines represent the fit with equation (2) mh200 (90 nm) mh146 (60 n m ) mh98 (16 nm) mh61 (12 nm) mh25 (65 nm) χ dc -1  (Oe g/emu) T (K) Fig. 3 (Colour online) inverse of dc susceptibility at high temperature regime for nanoparticle samples. The fit data show that Curie-Weiss law is applicable only at higher temperature, where as equation (2) is  applicable over a wide temperature range above T$_{C}$ of the samples.