I have synthesized cubic cobalt oxide (CoO) through solvothermal technique. XRD has confirmed the phase purity of the powder sample and the crystallite size is found to be about 29 nm (Scherrer equation). I have done MH measurements at 300 K and 10 K, both at 5 T. The MH curve is merely a straight line at room temperature and is giving a S-like pattern (with no saturation and very minute hysterisis) at 10 K (images attached).

I have not yet done the temperature-dependent magnetization (MT) measurements. Without MT measurement and rietveld analysis, is it possible to comment on the magnetic behaviour of the sample? could it be a case of antiferromagnetic (room temp.) to superparamagnetic (10 K) transition? If so, how can it be logically explained?